Safety valve for a dairy system component

ABSTRACT

A system for cleaning a dairy animal milker unit and applying dip to a dairy animal, the system includes a main control, an air supply, a water supply, a backflush fluid supply, a dip supply, a stall control for receiving the air, water, backflush fluid and dip supplies, and a safety valve that is adjacent to a downstream portion of the milker unit to control backflush and dip fluids being fed to the milker unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 15/887,573filed Feb. 2, 2018, which is a divisional of U.S. application Ser. No.15/366,858 filed Dec. 1, 2016, issued Feb. 6, 2018 under U.S. Pat. No.9,883,652, which is a divisional of U.S. application Ser. No. 14/588,094filed Dec. 31, 2014, issued Dec. 6, 2016 under U.S. Pat. No. 9,510,556,which is a divisional of U.S. application Ser. No. 13/269,835 filed Oct.10, 2011 issued Jul. 7, 2015 under U.S. Pat. No. 9,072,273, which is acontinuation of U.S. application Ser. No. 12/584,475 filed Sep. 4, 2009issued Oct. 11, 2011 under U.S. Pat. No. 8,033,247, is incorporatedherein by reference in their entireties.

FIELD AND BACKGROUND OF THE INVENTION

This invention relates generally to teat dip applicators andbackflushing systems for dairy animal milker units, and moreparticularly to automatic milker unit backflushing systems, teat dipapplicators, related components, and methods for safely and efficientlyapplying dips and backflushing milker units.

Dairy milking systems as they relate to the present invention include acluster of teat cups, each of which is matched with a flexible teat cupliner that is attached to a teat of a dairy animal with a vacuum. Vacuumis applied in pulses between the shell and liner to facilitate movementof the flexible liner to milk the dairy animals. Milk flows from the cowthrough each flexible liner and then through a short milk tube to amilker unit collecting bowl assembly, which collects milk from all ofthe animal's teats. This combination of elements is known as a milkerunit and can be used to milk cows, sheep, goats and other dairy animals.Each milker unit is used to milk multiple animals so it must besanitized, at least periodically, to prevent transmission of dirt andgerms into the milk, and to help prevent transmission of diseases fromanimal to animal.

Milk from individual animals flows from each collecting bowl assemblythrough a long milk tube and into a milk line that receives milk fromall of the milker units in the dairy. The milk is then chilled andstored in a milk tank. The milk lines and storage systems must not becontaminated with dirt, debris, chemicals, pathogens, or contaminatedmilk.

Various methods have been used to clean milker units. For example,milker units have been immersed into a bucket filled with a disinfectantsolution for cleaning. In a simple automated variation, milker units arepulled through a so-called “disinfection trough” or multiple troughsfilled with disinfectant solution. Other systems include automaticrinsing that is usually done from the downstream end of the long milktube and cleans the entire length of the long milk tube as well as themilker unit. This latter method involves very high consumption of waterand cleaning chemicals, and can waste milk that is in the long milk tubethat is otherwise salable. In all cases, a practically complete removalof the disinfectant solution from the milker unit must take place beforeit is applied to the next cow, so thorough rinsing and/or backflushingare necessary.

In addition, dairy animal teats have broadened milk ducts after milkingthat make them especially susceptible to new infection from mastitispathogens. To combat these pathogens, the teats can be treated with adisinfectant solution that adheres well to the teats and which usuallyalso contains a skin-care component. The application of thisdisinfectant solution is called dipping and can be done with a hand-helddipping cup into which the individual teats are introduced. Dip can alsobe applied using manual spray devices and foam applicators. Dipping witha cup is especially labor-intensive, but generally has a better successrate and a lower consumption of dipping solution than manual sprayingmethods.

Some spraying methods are automated to spray dip from a dipping arm ordipping bar. Automated sprayers are not precise and tend to consume muchmore dipping solution than manual dipping methods. Other early automaticteat dipping applicator systems applied dip upward from the short milktube toward the bottom of a teat at the end of milking, but beforedetachment from the milker unit. This arrangement provided someprotection, but it did not coat the entire teat uniformly. See U.S. Pat.No. 7,290,497. Others have suggested automated systems that apply dip toan upper teat portion, but most of these failed to provide: uniform dipcoverage on teats; consistent volumes of dip application over time; andprotection of downstream milk system components from being contaminatedby dip and other chemicals.

In particular, most prior automatic teat dip applicators and milker unitcleaner systems fail to adequately ensure that teat dip compositions andbackflushing fluids do not enter the long milk tube and contaminate thedairy milk lines. This problem can be caused by a number of factors, butone possible cause for contamination results from differential pressuresthat develop in dipping and backflushing devices that are connected tomilk lines. Differential pressures between the milk lines, and dippingand backflushing devices can cause seepage even through closed valvesand tight seals, so it is difficult to design, build, install, maintain,and use automated teat dip applicators and milker unit backflushingsystems that are safe and prevent contamination of dairy systems.

Thus, there is a need to provide backflushing and teat dip applicationautomatically and in a conveniently arranged system that also ensuresthat the dip solutions and backflushing fluids do not contaminate thedairy system and milk supply.

SUMMARY OF THE INVENTION

The present invention is directed to systems and methods thatautomatically backflush milker units and can automatically apply teatdip to dairy animal teats. Generally, when dip application is to beperformed with the present invention, it occurs automatically near theend of milking, when milk flow through the milker unit diminishes andvacuum is about to be shut off to detach the milker unit from a dairyanimal. Before detachment from the animal, the invention isolates themilker unit from the rest of the dairy system and delivers teat dip nearthe top of an animal's teats. A dip applicator in accordance with theinvention can include; a dip supply, a pump, suitable conduits, valves,and a manifold that directs substantially uniform volumes of dip to eachanimal teat. The invention can be adjusted to properly time dipdelivery, teat coverage, and dip rinsing for most types of teat dips.

After dip application, backflushing is performed by the presentinvention by continuing to seal off the milker unit from the downstreamdairy system components. Valves are operated and backflushing chemicals,water, and air are used to sanitize the milker unit. The backflushingoperation begins near a downstream portion of the milker unit and isdirected upstream toward the teat cups and liners. Cleaning the milkerunit with the invention is more thorough than cleaning just the cupliner and yet it does not waste milk in the long milk tube. The milkerunit and the invention itself can be rinsed with clean water afterbackflushing.

Automatically backflushing milker units cleans out milk and teat dippingsolution and prepares the milker unit for the next animal with minimalor no operator effort. Reduced operator effort results in moreconsistent dipping and milker unit cleaning and improved dairy herdhealth.

In accordance with the invention, the synchronization of the dipping andbackflushing operations and the protection of downstream milk systemcomponents can be performed by a system that includes; a main control,delivery hoses, an air supply, a water supply, a backflushing fluidsupply, a dip supply, a stall control, and a safety valve to seal thedownstream end of a milker unit from the rest of the dairy system. Thesystem can also include valve and controls to deliver backflushingfluids, water, and air through the safety valve and into the milkerunit. The dairy system downstream from the milker unit includes the longmilk tube and the rest of the dairy milk collecting, chilling, andstorage devices, and these are protected from contamination by thesafety valve and other system components.

One main control per milking parlor can be used and comprises anelectronic control, storage units and preparation of the dipping anddisinfectant solution. The main control can also monitor overall systemsafety and can generate appropriate warning signals or shut-downsignals. There can also be more than one main control, where eachcontrols a number of stalls within the overall dairy.

A stall control unit controls the system at each related milkingstation. It can control the time and sequence of the dipping,backflushing, and rinsing operations for individual milking stations.The stall control can also store dipping solution in a dosing valve inpreparation for each dipping process. The dip amount to be applied canbe adjusted to accommodate variations in teat dips, weather conditions,herd health, and any other relevant conditions using a dosing valve inaccordance with the present invention.

A safety valve in accordance with the invention can be formed integrallywith a milker unit collection bowl or be mounted on or near a downstreamportion of the milker unit. The safety valve automatically isolates themilker unit and dairy system from the dipping and backflushing devicesduring milking. The safety valve also automatically isolates the milkerunit from the rest of the milking system during the dipping andbackflushing processes to ensure that no dip or backflush fluids canflow into the milking system downstream from the milker unit. The safetyvalve and a dip valve can be formed in a single valve unit. Theinvention can be installed as an automatic backflush system or dipapplicator only, or it can include both. Also, an automatic backflushsystem can be installed initially and later have an automatic teat dipapplicator added. The safety valve can also be added to most existingmilker unit types and styles.

As stated above, the teat dip applicator applies dipping solution aftermilking and before the milker unit is released from the animal. Diptravels from the dip valve components in the safety valve to the linersthrough dip channels that are mounted either inside or outside of theteat cups (or shells). Consumption of teat dip with the presentinvention is comparable to the low consumption realized during manualdipping with a dipping cup. The dip can be distributed through the headof the teat shell liner, whereby the disinfectant solution can bedistributed all around by dome flow controllers formed in the inside ofthe head of the shell liners such as those disclosed in U.S. applicationSer. Nos. 12/215,706 and Ser. No. 12/157,924, U.S. Pat. No. 7,401,573,and Provisional Application 60/578,997 the disclosures of which areincorporated herein by reference. In this way, a single introduction ofteat dip to the shell liner is sufficient to distribute the dipuniformly in the area inside the liner head and onto the teat, and thenit is wiped on the length of the teat as the teat cup is removed.Gravity, pressure differential, and the wiping action of the linerduring detach all ensure full coverage of the teat from top to bottom.Controlling dip flow this way also reduces dip spray out of the milkerliner as the milker unit falls from an animal.

The milker unit safety valve ensures that disinfectant and teat dipcannot flow downstream from the safety valve and into the milk line,despite differential pressures in the milk lines and safety valve. Toprevent seepage past valves and seals, a safety valve in accordance withthe invention can include a type of valve arrangement known as“block-bleed-block.” Standard valves and seals can fail or allow seepagedue to differential pressure on opposite sides of seals used in milk,teat dip, and backflushing lines. The block-bleed-block function of theinvention prevents migration of disinfectant and teat dip through valvesand seals into the milk lines by supplying a pair of spaced apart valvesand a vent or “bleed” to atmosphere, with the vent being disposedbetween two seals. Multiple block-bleed-block arrangements can be usedin the invention to provide redundancy and added safety.

Also in accordance with the invention, there is provided a valve blockthat joins air, water, and backflushing supply lines and channels themto a common outlet for efficiency. The valve block also provides apressure bleeding vent between a pair of seals to further protect milklines from contamination.

Also, in accordance with the invention, a teat dip manifold can be usedto ensure more equal and consistent distribution of the dipping solutionto individual teat cups. The manifold can be disposed on or near themilker unit or safety valve The teat dip manifold can also include avalve arrangement that isolates each liner head dip tube or pairs ofliner head dip tubes from the others in the milker unit to preventadverse pressure differentials in the various tubes during milking.Adverse pressure differentials in these tubes can affect criticalmilking vacuum levels in the milker unit liner head, and the presentinvention eliminates or reduces these pressure differentials.

A method for backflushing a milker unit, in accordance with the presentinvention, includes the steps of: closing a safety valve tosubstantially seal off a downstream portion of the milker unit from adairy pipeline system; pumping backflush fluid through a safety valveand the milker unit; pumping water through the safety valve and milkerunit; forcing air through the safety valve and the milker unit; andopening the safety valve so that the milker unit is in fluidcommunication with the dairy pipeline system.

The step of closing the safety valve can include the step of: moving abackflushing piston from a milking position to a backflushing position,which can include the step of: forcing air into the safety valve to movea backflush piston from a milking position to a backflushing position.

The method for backflushing a milker unit can also include the step of:bleeding the safety valve at a safety valve vent, wherein the vent isdisposed between an upstream seal and a downstream seal when the safetyvalve is in the milking position and/or the backflushing position, andthe vent can be disposed between a backflush fluid supply in fluidcommunication with the safety valve and the downstream portion of themilker unit when the safety valve is in a milking position.

The present invention can perform the above steps for backflushing amilker unit in conjunction with a method for dipping dairy animal teatsis performed. The method for dipping dairy animal teats can include thesteps of: moving the backflushing piston to a backflushing position; andmoving a dip valve piston to a dipping position to allow dip to flowfrom a supply of pressurized dip to a dip channel that is in fluidcommunication with an upper portion of a teat shell liner, and this stepis performed before and/or during detachment of a milker unit from ananimal.

The present invention can accomplish one or more of the following:automate the dipping process to increase operator efficiency and reduceoperator fatigue; provide safe, individual disinfection of the teats toreduce pathogenic organisms on the teat; prevent transfer of infectionfrom animal to animal, and thus improvement of udder health of theentire herd; reduce or minimize chemical consumption (as opposed tospray or other automated dipping systems); improve uniformity of teatdip application; prevent chemical contamination of the milk and of thedownstream milk system lines; reduce water consumption duringbackflushing of the milker unit; and be retrofitted to nearly anyavailable milking unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective schematic view of a dairy harvesting facilityincluding a milker unit backflushing and teat dip applicator system inaccordance with the present invention;

FIG. 1B is a perspective schematic view of an alternate embodiment of adip applicator and backflushing system in accordance with the presentinvention;

FIG. 2A is a perspective view of a milker unit and safety valve inaccordance with the present invention;

FIG. 2B is a side view of the milker unit and safety valve of FIG. 2A;

FIG. 2C is a side view of an alternate embodiment of a milker unit andsafety valve arrangement in accordance with the present invention;

FIG. 3 is a front view of a main controller and supply tanks for abackflushing and teat dip applicator system in accordance with thepresent invention;

FIG. 4A is a perspective view of a stall control and a milker unit inthe milking position, the milker unit having the backflushing and teatdip applicator unit of the present invention;

FIG. 4B is a perspective view of the milking stall and milker unit ofFIG. 4A, with the milker unit in a backflushing position;

FIG. 5A is perspective view of a stall controller that can be used tocontrol backflushing and teat dipping at an associated milking stall inaccordance with the present invention;

FIG. 5B is front view of the stall controller of FIG. 5A;

FIG. 6A is a perspective view of a valve block in accordance with thepresent invention;

FIG. 6B is a left side view of the valve block of FIG. 6A with solenoidvalves removed;

FIG. 6C is a side cross sectional left side view of the valve block ofFIG. 6A with solenoid valves removed;

FIG. 6D is a side cross sectional front view of the valve block of FIG.6A with solenoid valves removed;

FIG. 7A is a perspective view from the lower right of a dosage valve inaccordance with the present invention;

FIG. 7B is a side cross sectional right view of a dosage valve inaccordance with the present invention;

FIG. 7C is a front cross sectional right view of a dosage valve inaccordance with the present invention in a dip ready position;

FIG. 7D is a front cross sectional right view of a dosage valve inaccordance with the present invention in a dipping position;

FIG. 7E is a disassembled perspective of a dosage valve in accordancewith the present invention;

FIG. 8A is a perspective view of a hose combination for communicatingmultiple fluids between components of the present invention and computerthat can program and reprogram the stall control;

FIG. 8B is a cross sectional view of the hose combination of FIG. 8A;

FIG. 9A is a cross sectional view of a dosing valve in accordance withthe present invention in a milking position;

FIG. 9B is a cross sectional view of the dosing valve of FIG. 9A in abackflush position;

FIG. 9C is a side cross sectional view of the milker unit safety valveof FIG. 9A in the milking position and illustrating bleed paths;

FIG. 9D is a partial side cross sectional view of the milker unit safetyvalve of FIG. 9A in a backflushing and dipping position in accordancewith the present invention;

FIG. 9E is a side cross sectional view of the safety valve of FIG. 9A ina backflush and dipping position;

FIG. 9F is a cross sectional perspective view of the safety valve ofFIG. 9A in a milk and dip block position and illustrating “bleed” pathsin accordance with the present invention;

FIG. 9G is the safety valve of FIG. 9A in the milking position and withthe housing removed;

FIG. 9H is the safety valve of FIG. 9A in the backflushing position withthe housing removed;

FIG. 10A is a perspective view of a seal insert in accordance with thepresent invention;

FIG. 10B is a cross sectional perspective view of the seal insert takenalong 10B-10B in FIG. 10A;

FIG. 11A is a perspective view of a backflush piston in accordance withthe present invention;

FIG. 11B is a side view of the backflush piston of FIG. 11A;

FIG. 11C is a top view of the backflush piston of FIG. 11A;

FIG. 12A is a perspective view of a backflush valve operation plate, inaccordance with the present invention;

FIG. 12B is a cross section of the plate taken along line 12B-12B inFIG. 12A;

FIG. 12C is a perspective view of an alternate embodiment of a backflushoperation plate in accordance with the present invention;

FIG. 12D is a cross section of the backflush operation plate taken alongline 12D-12D in FIG. 12C;

FIG. 13 is a perspective view of a safety valve piston connector inaccordance with the present invention;

FIG. 14A is a partial perspective view of an upper housing and relatedcomponents in accordance with the present invention;

FIG. 14B is a cross sectional perspective view of the safety valve andillustrating an air conduit through which pressurized air operates thebackflush piston and the dip piston, in accordance with the presentinvention;

FIGS. 14C is a partial cross sectional and perspective view of thesafety valve, and illustrating an air inlet through with pressurized airenters the safety valve to purge cleaning fluids from the safety valveand related components;

FIGS. 14D is a partial cross sectional and perspective view of thesafety valve, and illustrating an air inlet through with pressurized airenters the safety valve to purge cleaning fluids from the safety valveand related components;

FIG. 14E is a partial perspective view of the upper housing andillustrating a dip flow path through the safety valve;

FIG. 14F is a cross sectional side view of the upper housing and somerelated components in a dip position;

FIG. 15 is an exploded perspective view of a dip valve and top plate inaccordance with the present invention;

FIG. 16A is an exploded perspective view of a top plate, and dip inletand outlet chambers in the upper housing, of the present invention;

FIG. 16B is a perspective view of a top plate, in accordance with thepresent invention;

FIG. 16C is a cross sectional perspective view of the top plate of FIG.16B;

FIG. 16D is a perspective view of the underside of the top plate;

FIG. 17 is a perspective view of an umbrella valve for use in a safetyvalve in accordance with the present invention;

FIG. 18 is a perspective view of a safety valve cap in accordance withthe present invention;

FIG. 19A is a perspective view of a dip manifold in accordance with thepresent invention;

FIG. 19B is the dip manifold of FIG. 19A with the cover removed to showa diaphragm valve in accordance with the present invention;

FIG. 19C is the dip manifold of FIG. 19B with the diaphragm valveremoved to show dip flow paths through the dip manifold;

FIG. 19D is the drawing of FIG. 19C with the flow paths removed;

FIG. 19E is a perspective view of an alternate embodiment of a dipmanifold in accordance with the present invention with a cover removedto illustrate a diaphragm valve;

FIG. 19F is a cross section of the dip manifold with the diaphragm valveremoved to illustrate dip flow paths;

FIG. 19G is the dip manifold of FIG. 19F with the flow paths removed;

FIG. 19H is a diaphragm valve for use in the dip manifold;

FIG. 20A is an exploded perspective view of a teat cup assembly with aninternal dip channel for delivering dip, in accordance with the presentinvention;

FIG. 20B is a cross sectional view of the teat cup assembly of FIG. 20A;

FIG. 20C is a side view of an alternate teat cup assembly with anexternal dip channel for delivering dip, in accordance with the presentinvention;

FIG. 20D is a perspective view of another alternate embodiment of a teatcup assembly and dip channel for delivering dip, in accordance with thepresent invention;

FIG. 21A is a side elevational view of a milker liner in accordance withthe present invention;

FIG. 21B is a perspective view of a milker liner dome chamber inaccordance with the present invention;

FIG. 21C is a partial perspective cross-sectional view of a milker unitliner in accordance with the present invention;

FIG. 21D is a cross section of a liner and a teat cup of the presentinvention;

FIG. 22 is a chart illustrating a typical cycle of a dipping andbackflushing portion of the operation of a safety valve in accordancewith the present invention;

FIG. 23 is a chart illustrating a backflush operation in accordance withthe present invention;

FIG. 24 is a chart illustrating a dosage valve recharging cycle inaccordance with the present invention; and

FIG. 25 is a chart illustrating a backflushing operation in accordancewith the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1A, and 2A through 5B generally illustrate an automatic teat dipapplicator and milker unit backflushing system 20 disposed in a dairyharvesting facility 22, in accordance with the present invention.

The teat dip applicator and milker unit backflushing system 20 isreferred to herein as “the system 20” and preferably includes: a maincontrol 26; a compressed air supply 25; a backflush chemical supply 28;a water supply 29; a teat dip supply 30; a conduit 31 for housingappropriate hoses and piping 32; stall controls 36 for each milkingstall; a stall supply hose 38; a milker unit 40 for each stall, and asafety valve 60 for each milker unit 40. The main control 26 and othercontrols are connected to an appropriate electrical power supply (notillustrated).

The milker unit 40 (FIGS. 1A, 2A, 2B, and 2C) includes: a milker bowlcollector 44; four short milk tubes 46; four teat cups 48; four teat cupliners 50 disposed in the teat cups 48; a milker unit safety valve 60for controlling fluid flow for teat dipping and backflushing operations;and teat dip delivery channels 62 (FIG. 2A) for delivering teat dip toupper portions of an animal's teats. The teat cups 48 with liners 50 areattached to a dairy animal's teats and alternating vacuum (pulsation)through hoses (not illustrated) is applied to milk the animal. Milkflows from the liners 50, through the short milk tubes 46, into the bowland claw collector 44, and through the long milk tube 41 to the maindairy milk lines.

The system 20 preferably combines teat dipping and backflushingprocesses, but the system 20 can be within the scope of the presentinvention by including only a milker unit backflushing feature without ateat dip applicator or vice versa. Having only a backflushing feature isuseful for automatically backflushing each milker unit 40 after eachmilking or at least periodically to ensure optimum hygiene of the milkerunits 40. In a preferred embodiment, the teat dip applicator is a partof the same unit as the backflusher, but the teat dip applicatorcomponents can be added to the backflusher even after the safety valve60 has been installed on a milker unit 40. The system 20 of the presentinvention can be used in dairy harvesting facilities of anyconfiguration including rotary milking parlors.

FIG. 1B illustrates another teat dip and backflushing system thatincludes an applicator 831 that applies dip to a cow or other dairyanimal teat. The applicator 831 includes a control panel 832 and a dipmanifold 834. A teat cup shell 836, a liner 838, a first backflush valve840, a short milk tube 842, a milker unit collection bowl 844, milk line846, and a second backflush valve 848 are also provided to work as partof or in conjunction with the applicator 831.

The control panel 832 remotely controls operation of the teat dipapplication system 830.

It can be automated with suitable manual overrides or it can be operatedby manually engaging various control buttons in response to audibleand/or visual signals reflecting the stage of a milking and backflushoperation.

The control panel 832 controls the flow of air 837, water 839, teat dip841, and any appropriate three-way valve ventilation that may benecessary. A vent 845 is also provided. The control panel 832 canremotely control valves elsewhere within the system 830 or it canincorporate valves and hose connections for controlling air, water, teatdip, and valve ventilation.

The control panel 832 is in fluid communication with the dip manifold834 via a manifold hose 850. The dip manifold 834 is illustrated asfeeding a single teat dip applicator and milker unit combination, butthe manifold 834 preferably serves a number of liners 838 and milkerunit combinations. The dip manifold 834 is in fluid communication witheach teat dip liner 838 via a dip hose 852.

The dip hose 852 preferably tracks along the short milk tube 842, thefirst backflush valve 840, and passes into the teat cup shell 836 whereit is protected from damage. Alternatively, the dip hose 852 couldtravel an alternate route to the teat cup shell 836. The dip hose 852can also be routed on the exterior of the teat cup shell 836, or be partof an integral duct (not illustrated) formed in the teat cup shell 836.The dip hose 852 forms part of a fluid conduit through which teat dips,air, and water pass.

Once a sufficient amount of dip is applied, the dip manifold 834 shutsoff the flow of dip. Dip cannot be left inside the liner 838 because itmay contaminate milk from the next cow. Backflushing of the liner 838 istherefore desirable. There are at least two options to backflush theliner 838. In one option, the second backflush valve 848 is opened todeliver a backflushing fluid 859 such as water or a suitable chemicalinto the milk line 846, through the milker unit 844, the short milk tube842, the first backflush valve 840 (if present), and out of the liner838. In a second option, the first backflushing valve 840 is used, andonly the liner 838 is backflushed while the milk line 846 is isolated bythe backflushing valve 840.

Automatic operation of the system 830 relies on an end-of-milking signalfrom a milk sensor (not illustrated) that activates the control panel832 to shut off vacuum to the milker unit 844. The first backflush valve840 is then closed to isolate the liner head nozzle 864 from the milkerline 846 to protect the milk line 846 from being exposed to dip andbackflushing fluid 859. Preferably, only the second backflush valve 848is used, and it is activated by the control panel 832 to shut off themilk line 846 from the milker unit collection bowl 844.

The control panel 832 then operates a three-way valve to connect thecontrol panel 832 to the manifold hose 850 and delivers dip into themanifold hose 850, manifold 834, dip hose 852, liner head chamber 862,and liner head opening 864. The amount and pressure of the dip 851 iscontrolled by the valves and the pressure of the source of dip.

Air is then forced through the manifold hose 850, manifold 852, dip hose852, and liner head chamber 862 to force dip out of the liner headopening 864. As the milker unit 844 then begins detachment via astandard detacher mechanism (not illustrated), the liner head 860 mouthwipes dip down the teat sides and deposits an excess dip amount on theteat end.

Next, normal backflush cycles are used as described above to sanitizethe liner between milkings and rinse out any teat dip residue. Thesystem 830 is now ready to repeat the cycle. Main Control

Referring to the system 20 in more detail, as illustrated in FIGS. 1 and3, the main control 26, the air supply 25, the water supply 29, the dipsupply 30, and the backflush chemical container 28 are preferably in aroom separate from where the milker units 40 and milking operations arelocated. This is a preferred arrangement for safety and hygieneconsiderations, but other system configurations are possible.

FIG. 3 illustrates more details of the main control 26 that deliversair, water, dip (when included as part of the system), and backflushsolution in a precise controlled manner to the stall controls 36 locatedin the dairy parlor 22. The main control 21 is preferably containedwithin a housing or cabinet for protection against harsh dairyconditions. The main control 26 includes a programmable device 21 thatcan, for example, store information, control operation sequences,monitor operations, receive data regarding the condition of the system20, analyze possible problems, generate maintenance prompts, and providecritical control in case of problems. If such problems arise, the maincontrol 26 can be programmed to generate an appropriate signal, such assound, light or written display.

The main control programmable device 21 is preferably programmed tomonitor and control all of the functions of the devices associated withthe main control 26, as well as, communicate with, respond to and/orcontrol; stall controls 36, computers, other data input devices,including sensors and manual controls. For example, the main control 26can monitors a number of system parameters such as: 1) dip applicationpressure; 2) water pressure; and 3) air pressure of one or more airsupplies, and adjust these parameters by modifying operational controlsor adjust one or more pressure regulators 68. The programmable device 21is preferably an I/O 88 PCB circuit board used as an electronicmonitoring device, but other types of devices can be used to accommodateparticular dairy installations and needs. There can also be mounted onthe main control an on/off switch, indicator lights, signal lights,sound alarms, key pads, other input devices, signaling devices and/orany other type of interactive device. Grommets for wire/cable connectorscan be part of a housing for the programmable device 21, as well.

The dip application pressure should be kept relatively constant tomaintain a consistent dipping process with minimum lag time, airbubbles, or other inconsistencies. Dip from dip supply 30 (not to scalein FIG. 3) is pumped by a dip pump 33 and controlled by a regulator 35.Dip pressure can be monitored at various locations and adjusted toaccount for pressure drops/increases through the dip applicationcomponents, including a dip filter 39, mounted on the main control 26.The dip supply 30 can store a premixed dip, a dip concentrate, dry dipingredient, or other dip ingredient, to be mixed automatically by themain control 26. It can include more than one container and can includea water source for in situ mixing of dip.

Backflush fluids can be drawn from multiple sources including thebackflush chemical container 28 which is not shown to scale, but isrepresentative of a single chemical supply either premixed orconcentrated, a liquid or solid chemical mixer, multiple chemicalsupplies or any other source of chemicals that may be desired for use inbackflushing milker units. A backflushing flow or dosing meter and/orpump 53 is preferably used to mix a concentrate from chemical container28 with water and to control flow of backflushing chemicals to the stallcontrol or directly to a safety valve 60. When concentrates are used,mixing with water or other fluids can take place at or be controlled bythe main control 26. Various types of mixing controls and vessels can beused, but a Dosatron, Model D25RE2 available from Dosatron InternationalInc. of Clearwater, Fla. 33765, U.S.A, is preferred. Appropriatefilters, sensing devices, and sampling devices for all of the suppliescan be used as well.

Air and water pressures should not be allowed to drift outside ofpredetermined ranges because insufficient air and water pressures canresult in ineffective valve operations and inconsistent cleaning and/orteat dip application. If an unacceptable condition occurs, normaloperation of the invention can be shut down and/or alarms can beinitiated.

Air pressure is generated by one or more compressors (not illustrated)and regulated by a regulator 37, controlled by an air monitoring switch45, and filtered by an air coalescing filter 47. The air supply 25 isset at an appropriate outlet pressure, preferably between about 50 to 70psi, to operate related components. Optimum air pressure will depend ona number of factors, including the number of milker units 40 beingserved and hose length from the air compressor 28 to the milker units40. More than one air supply line can be used and controlled by the maincontrol 26.

Water inlet pressure can be generated by local sources or a pump used aspart of the system 20. Water inlet pressure is monitored by switch 49and be filtered. The water supply 29 can be any suitable source of waterwith temperatures, pH, and chemical properties that are compatible withthe system 20 and related chemical solutions such as teat dipconcentrates, backflushing chemical concentrates, or simply as a finalrinse of milker units 40 after a backflushing operation. A conditioningsystem (not illustrated) can be included if the pH or other propertiesof the local water source is incompatible with the necessary chemicalsolutions and/or to minimize corrosion of system components.

In a preferred embodiment, one dip line, one water line and onebackflush solution line extend between the main control 26 and the stallcontrol 36 and can be combined as depicted with the hose combinationsuch as the hose combination 38 illustrated in FIGS. 8A and 8B. Two airlines are preferred because one air supply is used for reliable safetyvalve, valve block, and dosing valve, and the second air supply is usedfor slugging backflushing fluids through the safety valve and milkerunit. A single air line can communicate pressurized air from the maincontrol 26 to a convenient location in the dairy before splitting thatline into two separate lines. The split should be at a location thatresults in each air supply line having pressurized air that is notadversely influenced by pressure fluctuations in the other air supplyline. The lines are preferably “pass through” types that allow forarrangement of the stall controls in “series” to reduce the number ofhoses leaving the main control 26.

A liquid level assembly 57 is preferably used for the dip and backflushsolution supply drums to provide information to the main control 26regarding status of liquid levels. The assembly 57 preferably includes adraw tube 59 with inlet screen/filter, a standard drum interfaceconnector, and a reed switch 61. The reed switch 61 provides a signal tothe main control 26 and to parlor management software, if desired,indicating when the supply drum is nearly empty. An example of such anassembly is illustrated in the drum 30 in FIG. 3.

Supply Conduits

The pipelines and hoses 32 are sized and configured to meet therequirements of individual dairy harvesting facility. They may be routedtogether through the conduit 31 for protection and efficiency and toaccommodate the pass through supplies described above. The conduit 31can be plastic, such as PVC, metal or other suitable material.

Stall Control

A stall control 36 is dedicated to each milking stall (See FIGS. 4A, 4B,5A, and 5B) in the dairy harvesting facility 22. The stall control 36can be mounted using a base unit 101 in any convenient location near itsrespective stall, including under a platform in a milking parlor asdepicted in FIGS. 4A and 4B. Visual confirmation of the physical safetyfeatures within the safety valve 60 and other components is preferred,and appropriate positioning of the components is, therefore, desired.The stall control 36 can also be mounted to a wall, under the curb 54 oron top of the vacuum lines in swing-over parlor applications.

The stall control 36 is responsible for initiating a teat dipapplication and/or backflushing at the end of milking. Other milkingoperations can also be controlled at each stall control 36. Electricalpower is supplied through a separate conduit (not illustrated). FIG. 4Aillustrates a milking position and FIG. 4B illustrates a backflushingposition. The stall control 36 is preferably located under the parlorcurb 54 (in FIGS. 4A and 4B) where it is out of the way, yet readilyvisible to an operator.

Preferably, the electronic control 80 includes a protective housing orcabinet and a stall control card 86 such as a programmable circuit board(“PCB”) for storing control parameters, monitoring, and signaling isprovided. A suitable control card 86 is an I/O 88 PCB circuit board.Other types of programmable controls can also be used. The stall control36 preferably includes an interface for a computer 55 or otherprogramming device, sensors or monitoring devices. The computer 55 canalso be used to program and monitor data from the main control 26. Theelectronic control 80 can also include grommets for connecting wires andcables, and it can include signaling lights, key pads, or otherinteractive components.

Referring to FIGS. 5A and 5B, the stall control 36 activates thebackflushing and/or dipping operations after sensing that milk flow fromthe animal has ended or after a detacher is activated to remove themilker unit 40 from an animal. The operations begin with the safetyvalve 60 being activated to close downstream milk lines, such as thelong milk tube 41 and protect the milk supply. A dose of teat dip willbe pushed preferably with an air operated piston for speed, reliabilityand reduced foaming from a dosing valve 84 through a manifold 540,delivery channels 62 and a dome of a milker unit liner 50, and appliedto an animal's teats.

The stall control 36 illustrated in FIGS. 5A and 5B preferably includesthree primary components: an electronic control 86, a valve block 610,and a dosing valve 84 (when a dip applicator is included). Each stallhas a control 86 and all are preferably programmed identically toprovide a sequence of safety valve operation that is necessary toperform dipping and backflush or backflush only functions. Theelectronic control 80 can include a circuit board such as a standardeight input eight output circuit board at each stall to interface with amilking control (not illustrated) so the dipping and backflush processesare performed at a proper time and in a proper sequence. There areseveral variables that allow the sequence of operation to be variedwithin predetermined safe ranges, including: dip viscosity andcomposition, backflush chemical viscosity and composition, the amount ofavailable time to perform each task, and ambient conditions.

Further, some variables can be adjusted to customize the sequence basedon particular equipment or operation needs, however all stalls arepreferably set similarly within any particular operation to ensureuniform treatment of all milker units 40 and all dairy animals.Variables such as hose size, hose length, distance of stalls from themain control 26, dip types, individual animal needs, condition of theequipment, ambient conditions, and many other variables can beconsidered and programmed into the electronic control 80 to provideconsistent operation and optimum dairy animal health. Further,monitoring devices can be used at various points in the system 20 tosignal the stall control cards 86 to adjust appropriate parameters.“Fuzzy logic” controllers can be used to continually adjust parametersas conditions change in a dairy and/or with the dairy animals.

The valve block 610, programmable device 86, and the adjustable dosingvalve 84 ensure that equal and consistent amounts of backflush fluidsand dip are used in each operational cycle. The manifold 540 is attachedto a milker unit 40 and is desirable to ensure that each dose of dip isdivided equally for each animal teat.

The stall control 36 controls delivery of air, water, and chemicals tothe milker unit 40 through a hose or hoses 38. These hoses 38 are of anysuitable size and length and are preferably made of a material that issuitable for use in a harsh dairy environment, yet flexible enough tonot influence the milker unit 40 while on a dairy animal. Using combinedhoses 38 minimizes the number of hose assemblies necessary to operatethe system and facilitates a flexible bundling of hoses. A notch can bemade in a hose bundle web for joining of all hoses using a standardplastic tie or other suitable means in an organized yet flexible way.Further, the hoses 38 are preferably arranged next to a long milk tube41 through which milk flows from the milker unit 40 to the dairyharvesting facilities main milk lines. This arrangement reduces thechances of the hose 38 from being damaged by a dairy animal and it makesattachment of the milker unit 40 easier because the hoses 38 will notinterfere a with an operator's movements.

The stall control 36 can be equipped with a manual ON/OFF-Reset switch99 which can shut down the dipping and/or backflush processes for agiven stall in case of problem. Power for the stall control 36 can bewired directly from a source or be relayed from the main control 26.Valve Block

FIGS. 6A through 6D illustrate a valve block 610 in which a number ofvalves are provided for supplying multiple medias (air, water, andbackflush fluids) through a common outlet 637 to a backflush inlet 186on the safety valve 60 (FIG. 14A). The valve block 610 includes ahousing 613 that defines an axial chamber 619 in which a spool 621 isdisposed to slide between a milking position (FIG. 6C) and abackflushing position (FIG. 6D). The axial chamber 619 includes an upperbell portion 623 and a lower bell portion 625.

The housing 613 is preferably oriented vertically, as depicted, toprovide drainage of fluids through a drain 634 (FIG. 6B), but otherorientations can be used. Preferably, the valve block 610 housing 613 ismade of Radel R5000 from Piedmont Plastics, Inc. of Charlotte, N.C. andavailable from distributors throughout the United States, or othertranslucent plastic or glass material to provide superior chemicalresistance and clarity for operation and maintenance inspections. Thevalve block 610 housing 613 is preferably arranged and molded as anintegral piece as depicted. Other materials can be used for the valveblock 610 and related components, and the valve block 610 can be formedfrom one or more parts. Flanges 609 or other connectors can be joined toor molded integrally with the valve housing 613 to permit convenientmounting with snap-in features, screws, or other suitable fasteners.

The valve block housing 613 includes several pass-through inlets 614though which air, water or backflushing fluids flow. Pass though inlets614 are used so that a number of valve blocks can be arranged in seriesand supplied with air, water, or backflushing fluids from a commonsource. Other arrangements can be used, but arranging valve blocks inseries requires fewer hoses for air, water, and backflushing fluids andless demand on pumps and other supply components. Flow through the passthrough inlets 614 can be in either direction to accommodate a varietyof dairy layouts.

Most of the pass-through inlets 614 communicate with a corresponding anddedicated block inlet 614 a that is controlled by its respective valveto permit entry of a predetermined fluid into a chamber 619 throughconduits 614 b. One exception is the pass through inlet 614 for thesecond air valve 612, which communicates with the lower bell portion 625of the axial chamber 619 at a position under the spool 621 via passages635 a and 635 b so that pressurized air can force the spool 621 into thebackflushing position (FIG. 6D), when desired.

Preferably, the valve block 610 includes five valves, as depicted inFIG. 6A including: a first air valve 611 that provides air directly tooperate the milker unit milk safety valve 60 for dipping andbackflushing; a second air valve 612 that moves a valve block safetyspool 621 into place and provides air pressure to push dip in the teatdip delivery tubes 62 between the safety valve 60 and the liner 50 ontoa teat; a third air valve 620 provides air for slugging backflush fluidsand for complete surface rinsing and vigorous scrubbing of interiorsafety valve 60 surfaces; a water valve 622 that provides water to beused to rinse the milker unit 40 after backflushing and the safety valve60 in a self-rinse cycle; and a backflush solution valve 624 thatprovides one or more chemical solutions for backflushing the milker unit40.

All valves are preferably solenoid valves, including the third air valve620, which is preferably a pilot operated valve that ensures air flowfor backflush slugging. Also preferably, the backflush valve 624 is madeof stainless steel or other material that resists corrosion from thebackflushing fluids. For ease of reference, each valve is joined to thevalve block 610 at a seat and each seat is designated in FIGS. 6B and 6Cwith a numeral matching its respective valve and including the suffix“a”, so that valve 620 is mounted on seat 620 a, for example.

The first air valve 611 is reserved for only operating the safety valve60 only to help ensure complete, independent, and safe operation of thesafety valve 60. The first air valve 611 operates independently from theother backflush valves on the valve block 610 because the safety valve60 must operate during dipping operations, and before and duringbackflushing operations. The independent operation also avoids pressurefluctuations that could result in from sharing air supply pressure withother system components. The air from air valve 611 exits the valveblock 610 through a separate outlet 615 for this reason. The first airvalve 611 could be separate from the valve block 610 and mountedelsewhere in the system because it does not use the common outlet 637.Nonetheless, the valve block 610 provides a convenient mounting locationand helps keep all of the hoses for the pass-through inlets 614organized.

The second air valve 612 supplies air to the dosing valve 84 (describedbelow) through an outlet 617. The air inlet 614 a preferably receivesair from the same air source that supplies valve 611 and the safetyvalve 60. Air from this air supply can be supplied through suitablehoses, conduits, or the like. A single air supply for the safety valve60, the valve block 610, and the dosing valve 84 is adequate because ofthe low air pressure demands of these devices.

The spool 621 (FIGS. 6C and 6D) includes an upper valve head 626 and alower valve head 628. The upper valve head 626 and the lower valve head628 each define an annular groove in which seals 626 a and 628 a aredisposed, respectively. The seals 626 a and 628 a are preferably u-cupseals oriented as depicted to provide a sealing function in onedirection each. U-cup seals provide satisfactory sealing properties andreduce friction between the seals and the central housing 613 so thatthe spool 621 moves relatively easily with a relatively low airpressure.

The seals 626 a and 628 a oppose each other to seal the axial chamber619 at their respective ends. This seal orientation can permit fluid topass into the axial chamber 619. The spool 621 can be made of anysuitable material such as stainless steel, stable plastic, or othermaterial. The seals 626 a and 628 a can be made of Viton (FKM) or anyrubber, silicone or other suitable material or the seals can be formedintegrally with the spool 621.

A valve block spring 630 biases the spool 621 toward the milkingposition (FIG. 6C). The valve block spring 630 engages a seat 631 on theupper valve head 626 and is contained within cap 633. An alignment rod639 extending from the upper valve head 626 of the spool 621 fits insocket 641 (FIG. 6C) formed in a cap 633 to maintain proper alignment ofthe spool 621 when moving between the milking position (FIG. 6C) and thebackflushing position (FIG. 6D).

In the milking position (FIG. 6C), the spool 621 is forced by the valveblock spring 630 to engage the upper valve head seal 626 a with thewalls of the axial chamber 619 to seal the common outlet 637 from thechamber 619 with an end seal 626 a. The lower valve head 628 is forceddown into the lower bell portion 625 and does not engage the walls ofthe axial chamber 619, but the lower valve head 628 includes a recess629 that fits around and seals the air outlet 617 while permittingdrainage of residual fluids through drain 634. In the milking position,there is a space between the spool 621 and the walls of the axialchamber 619 that extends between most of the length of the axial chamber619. The drain (or vent) 634 is in communication with the axial chamber619 to “bleed” any differential pressure between the valves and the milkline thereby minimizing migration of dips and backflush fluids into themilk lines. The drain 634 is preferably located near the bottom of theaxial chamber 619 to provide a drain for any fluids in the axial chamber619 when the spool 621 is in the milking position.

The valve block 610 is preferably controlled by the stall control 36 tomove to the backflushing position after the dipping operation. In thebackflushing position (FIG. 6D), the spool 621 is forced (upward asillustrated) against the bias of the valve block spring 630 bypressurized air entering the inlet 635 to move the lower valve head 628seals 627 and 628 a into sealing engagement with the walls of the axialchamber 619 to seal the vent 634 and open the air outlet 617 to thedosing valve 84. In the backflush position, the upper seal head 628 doesnot seal anything because it is disposed in the upper bell portion 623,and opens the axial chamber 619 to the common outlet 637.

The inlets for the air valve 620, the water valve 622, and thebackflushing fluid valve 624 all communicate with the axial chamber 619through inlets 614 a, so that all of these fluids can flow through theaxial chamber 619 and out of common outlet 637 when their respectivevalves are opened and the spool 621 is in the backflushing position. Thefluids do not typically flow together, instead the various valves firein a predetermined sequence to supply air, water or backflushing fluidat the specific time needed by the safety valve 60, as described below.All hose connections to the valve block 610 and other components of thesystem 20 can be made with any suitable connection, including a JohnGuest fitting, as depicted in outlet 617. Dosing Valve

When the system 20 includes a teat dipping option, it is preferred thatone or more dosing valves 84 be used at each stall. FIGS. 7A to 7Eillustrate an example of a dosing valve 84 for use in the presentinvention is preferably pre-wired to and mounted on the stall control36. The dosing valve 84 is filled with dip after each completed dippingoperation in preparation for the next dipping operation. Each dosingvalve setting should be adjusted to provide substantially the sameamount of dip at each stall for consistent treatment of animals. Theamount of dip desired will depend on the type of dip used and operatorpreference with regard to the amount of dip that will be visible on theteat after dipping.

Further, more than one dosing valve 84 can be used to apply differentdips, dip concentrations, medicaments, and the like to individual teats.When this latter option is desired, the various controls, especially thestall control 36, can receive cow identification information fromautomated cow identification systems, and provide specialized teat dipapplications to individual animals.

The dosing valve 84 includes a housing 432, a dip inlet 434, a dip feed436, a dip outlet 438, a chamber adjustment mechanism 440, a solenoidvalve 444, and an air chase outlet 446. The dosing valve 84 operateselectronically and pneumatically. The housing 432 is preferably made ofa translucent plastic material such as Radel R5000 or any FDA approvedmaterial, so that visual confirmation of the adjustment mechanism 440position, the presence or absence of teat dip, and maintenance are allsimplified.

The housing 432 defines a chamber 450 (FIGS. 7B, 7C, and 7D) in whichteat dip is measured and stored prior to being pumped to the safetyvalve 60. Generally, the volume of the chamber 450 can be changed byadjusting the chamber adjustment mechanism 440 in or out of the chamber450. The volume of the chamber 450 is preferably set by comparing theadjustment screw 440 position to embossments 451 (FIG. 7A) on the sideof the housing 432, in amounts from about six to about fourteenmilliliters, for example. Other types of measuring markings or devicescan be used.

The dip inlet 434 is connected via a hose (not illustrated) to apressurized source of dip at the main control panel 26. The dip outlet438 is connected to the safety valve 60 via a hose or other suitabledevice. The housing 432 also defines a vent hole 439, to vent air as dipenters the chamber 450 and to prevent air from getting into dip in casean internal seal leaks, which would reduce the volume of dip deliveredto teats.

The dip feed 436 is connected via a hose to an adjacent stall's dosingvalve 84, so that the dosing valves 84 are arranged in series to receivepressurized dip from the main control 26. Such an arrangement reducesthe number and lengths of dip hoses from the main control 26, andbetween stall controls 36.

The chamber adjustment mechanism 440 preferably includes a screw housing458, a threaded shaft 460, a shaft head portion 462 FIG. 7B), a headseal 464, and a hollow conduit 466 that extends through the length ofthe threaded shaft 460.

The screw housing 458 has a u-shaped portion 467 (FIG. 7E) with a recess469 that mates with an upper rim 468 of the dosing valve housing 432 toconnect the two housings together. The screw housing 458 furtherincludes flanges 472 with notches or holes 474 through which screws canbe inserted to mount the dosing valve 84 to a wall or plate near thestall control 36.

The housing 432 rim 468 is inserted laterally into a back side of thescrew housing 458 so that the dosing valve 84 is unable to becomedisconnected when the screw housing 458 is mounted to a support surfacewith screws. Additionally, the threaded shaft 460 itself acts to preventdisconnection because the two housings are unable to move laterallyrelative to one another when the threaded shaft 460 extends into thechamber 450.

A lower end of the threaded shaft 460 is formed with or joined to thehead portion 462.

The head portion 462 is preferably sized to mate with the chamber 450. Aseal 464 is used to substantially seal an annular surface of the headportion 462 with the housing chamber 450. The seal is preferably a u-cupseal.

The threaded shaft 460 includes exterior threads that mate with interiorthreads in the screw housing 458. The exterior threads 480 arepreferably discontinuous 480 to reduce tooling cost. The threaded shaft460 also includes an upper knurled portion 482 to facilitate manualadjustment even when the operator is wearing gloves or the surfaces arewet. The knurl 482 also connects to an air line used to operate thedosage valve 84 to push a spool-shaped piston 500 down and the dip outof the dosing valve 84.

As illustrated in FIG. 7C and 7D, the spool-shaped piston 500 isdisposed inside the housing chamber 450. The spool-shaped piston 500includes upper and lower seals 502 that slidably seal a central portion503 of the spool-shaped piston 500 with the inside of the chamber 450.Pressurized dip is allowed into the chamber 450 through the dip inlet434 by the valve 444. The pressurized dip forces the spool-shaped piston500 to slide toward the threaded shaft 460 where it is stopped to definea predetermined volume defined in the chamber 450 between the spoolpiston 500 and the dip outlet 438. This is a “dip ready” position.

To apply dip, pressurized air is fed from the second air valve 612 inthe valve block 610 (FIG. 6A) to enter the hollow conduit 466 and pushthe spool-shaped piston 500 toward the dip outlet 438 to force dip outof the outlet 438 toward the safety valve 60. The dip outlet 438preferably extends into the chamber 450, as illustrated, to act as stopfor the spool-shaped piston 500. An air hose between the second airvalve 612 in the valve block 610 is not illustrated in FIGS. 6A-7E, butsee FIGS. 8A and 8B for a representative hose example.

When the spool 500 reaches the bottom of the chamber 450, the dosingvalve is in a “the dip empty” position. With the spool piston 500 inthis position, the air chase outlet 446 is no longer blocked, andpressurized air that moved the spool 500 now exits the chamber 450through the chase outlet 446 and moves through a hose, and enters thesafety valve 60 to provide an air chase for the dip moving from thesafety valve 60 to the milker unit. Thus, the same source of pressurizedair used to feed a pressurized volume of dip also, in precise sequence,provides a desired air chase for that dip without using controllers,extra valves or other devices.

After an appropriate air chase interval, the solenoid valve 444 operatesto allow dip to flow through the dip feed inlet 436 to fill the chamber450 and push the spool-shaped piston 500 to a “dip ready” position (FIG.7C). The solenoid valve 444 includes electrical contacts 449. Afterfilling the chamber 450 with dip, the solenoid valve 444 closes toprevent pressurized dip from the main control 26 from damaging sealsinside the dosing valve 84.

In the overall system of the present invention, other forms of dosingvalve mechanisms can be used, and dosing valves are not absolutelynecessary. Nonetheless, the above-described dosing valve 84 isparticularly effective, simple, and reliable for providing a consistentamount of dip and chase air in a timely fashion.

Hose to Safety Valve

As stated above, automatic teat dip applicator installations preferablyinclude one set (or bundle) of four hoses 38 (FIGS. 8A and 8B) toconnect the stall control 36 to the safety valve 60.

A backflush hose 141 provides air pressure to move the milk safety valve60 into position during dipping and backflushing operations. The secondhose 145 provides the large capacity connection for backflush solution.

A teat dip hose 140 provides dip to the milker unit 40 and a secondsmall tube 143 for providing a fluid “dip chase” that is preferably air.As stated above, the dip chase 143 reduces the amount of dip requiredand more completely utilizes the dip required for each milking becauseonce the dosing valve 84 has pushed the dip to the safety valve 60 andon to the liner 50, any dip that remains in the hose between the safetyvalve 60 and the liner 50 would otherwise be flushed and wasted in thebackflush process. The teat dip hose 140 is preferably emptied beforemilking to prevent any residual dip from getting into the milk.

Milker Unit

As depicted in FIGS. 2, 2B, and 2C, the milker unit 40 can be used withthe collection bowl 44 as depicted in WO 2009/077607 A1, WO 2008/138862A2, US 2009/0050062 A1, US 2008/0276871 A1, as well as, other bowl andclaw arrangements. The system 20 and/or any of the individual componentsof the system can be retrofitted to existing milker units 40 byconnecting the safety valve 60 downstream from the milker unit 40, andpreferably near the milker unit 40 because any milk upstream from thesafety valve 60 will be flushed out in the backflushing operation.

In FIGS. 1 and 4A, the milker unit 40 is depicted in a milking positionwith the bowl 44 on the lower portion and the teat cups 48 and liners 50directed upwardly. This is the position of the milker unit 40 duringautomatic teat dip application. The backflushing operation will takeplace when the milker unit 40 is disconnected from a dairy animal (FIG.4B) and the teat cups 48 and liners 50 are opened sideways or downwardfor draining backflushing fluids. It is preferred that the entire milkerunit 40 be upside down during backflushing for complete drainage.Alternatively, a vacuum purge method may be employed whereby theremaining backflush solution in the milk bowl 44 is drawn back throughthe backflush supply circuit to the stall control 36 with vacuum andthen retained for future use or purged from the system 20.

Safety Valve Safety Valve Overview

The safety valve 60 of the present invention is situated on or near amilker unit to seal and protect downstream dairy milk lines from teatdip and cleaning fluids that are fed through the safety valve toupstream milker unit components. All of the fluids, including dip,cleansers, water, and air pass through the safety valve 60.

The safety valve 60 has a housing with various inlets, outlets, andvents through which the fluids flow. These fluid flows are controlled byseveral moving parts including two pistons and a connector between thetwo pistons, all of which are moved by springs and an air-actuatedoperation plate. A set of three umbrella valves is also used inside thehousing to control the flow of some of the fluids. A number of specialseal and vent arrangements are used in the housing to prevent unwantedseepage of fluids through the safety valve.

Safety Valve Detailed Description

The milker unit safety valve 60 is placed at or near the downstream endof the milker unit 40, milk remaining in the long milk tube will not beflushed. In new milker units 40, the safety valve 60 can be joined to ormolded integrally with the milker unit collection bowl so that thebackflushing operation flushes out the milker unit 40 including thecollection bowl 44, the short milk tubes 46, and the liners 50. (FIGS.2A, 2B.) Further, a system 20 installed with only a backflushingfunction can later have an automatic teat dipping feature added, asdescribed in more detail below.

Short milk tubes 46 are also flushed and they can be of any designbecause none of the system 20 components connects to or passes throughthe short milk tubes 46. Nonetheless, the backflushing operation beginsdownstream from the short milk tubes 46, so any milk or other materialin the short milk tubes 46 will be cleaned out in the backflushingoperation.

The safety valve 60 is depicted separate from any milker unit in FIGS.9A through 9F. Generally, the safety valve 60 ensures that backflushingfluids and teat dip do not contaminate milk in the dairy componentsdownstream from the milker unit 40. The safety valve 60 also dispensesbackflushing fluid and teat dip at appropriate intervals, and is capableof flushing and rinsing itself to ensure proper hygiene at all points inthe system. The safety valve 60 can be made integrally with thecollection bowl 44 of a milker unit 40 or be a separate unit connectedto an outlet of the milker unit 40 or be joined with a short section ofmilk tube 61 between the milker unit 40 and the safety valve 60. (See:FIG. 2C.) Dip passes through a tube 65 to the manifold 170.

The safety valve 60 must move between a milking position (FIG. 9A) and abackflushing position (FIG. 9B) to prevent contamination of the milksupply. It is noted that the terms “milking position” and “backflushingposition” are used to designate the position of a backflush piston 120,and that functions other than milking and backflushing can take placewhen the backflush piston 120 is in these positions.

Due to pressure differentials between milk lines, backflush lines, diplines, and atmospheric pressure, it is desirable to do more than simplyseal such lines from the milk supply because fluids can seep or migratepast valves and seals when seals are used alone. With the presentinvention, the pressure differentials are avoided with vents exposed toatmospheric pressure to “bleed off” any pressure differential that maycause unwanted seepage past a seal. In this manner, pressures on eachside of the safety valve 60 are isolated from one another and migrationof chemicals, air, and other fluids into the milk supply is prevented.

Generally in the present invention, the vents that “bleed” the pressuredifferentials are disposed between pairs of seals. This arrangementresults in a block at one seal, a bleed at the vent, and another blockat the other seal for a “block-bleed-block” feature that preventsseepage and ensures safety of the milk supply from backflushing anddipping fluids.

As depicted in FIGS. 9A through 9F, the safety valve 60, a preferredembodiment generally includes a housing that is assembled from a lowerhousing 70, and an upper housing 74, and the upper housing 74 is coveredby a cap 76. These elements are secured to one another with screws 78(FIG. 9F), or any other suitable connectors, including but not limitedto snap fittings, threaded housing components or being molded integrallywith one another. Separate housing portions are preferred for ease ofmanufacture and assembly, but other housing arrangements are possible.Also, the safety valve 60 can be joined to the milker unit 40 with asuitable connector such as a screw 81.

Preferably, the lower housing 70, upper housing 74, and cap 76 are madeof a translucent material such as Radel R5000 formulationpoly-phenylsulfone material, or FDA and 3A approved material to providefor visual inspection without disassembly of the safety valve 60.Further, translucent materials provide visual indication of a leakand/or if the leaked material exits a vent. It is preferred that anyleakage will exit a vent that an operator can see.

The lower housing 70 includes a milk inlet 62, a milk outlet 64, a pairof pulsation conduits 82, a pulsation outlet 83, and a hanger 66. Themilk inlet 62 is sized and shaped as necessary to mate with and besecured by a screw 81 to a milker unit 40′s downstream outlet.

Alternatively, the milk inlet 62 of the safety valve 60 can be connectedto a short section of tube 61 (FIG. 2C) disposed between the safetyvalve 60 and the milker unit 40. The short tube section 61 in such anembodiment is preferably short so that the safety valve 60 is close tothe milker unit 40. This arrangement places the safety valve 60downstream from the milker unit 40 so that the milker unit 40 isbackflushed after each milking operation, but the long milk tube 41 oronly a small portion of the long milk tube 41 is backflushed to minimizethe quantity of milk that will be rinsed out of the long milk tube. Thesafety valve 60 can also be an integral part of the milker unit 40 bymolding, bolting, screwing, gluing or otherwise attaching the safetyvalve 60 to the milker unit 40.

It is noted that the terms “upstream” and “downstream” refer to thedirection milk flows (right to left and identified as “M” in FIGS. 9Aand 9B), from the dairy animal to the milker unit 40, through the longmilk tube 41, and to the dairy milk's collecting, chilling, and storingfacilities. During backflushing operations, backflushing and rinsingfluids flow upstream in the opposite direction of the milk flow. Dipdoes not pass through the path M because dip travels through a separatetube toward the dip manifold.

The pulsation conduits 82 and outlets 83 mate with a pulsation port onthe milker unit 40 to provide vacuum pulsation for the milkingoperation. This pass through of vacuum is not necessary in the FIG. 2cembodiment because there is adequate clearance between the milker unit40 and the safety valve 60 to feed vacuum lines directly to the vacuumport 85 on the milker unit 40. The hanger 66 can be secured to a milkerunit detacher mechanism (not illustrated) so that the milker unit 40 issupported above the floor or deck when not attached to a dairy animal.The hanger 66 may be unnecessary if the milker unit 40 includes such afeature.

The lower housing 70 generally defines a chamber 90 that is preferablyshaped as a cylindrical cavity, but other shapes could be used to ensureproper arrangement of parts. Milk flows through a lowermost portion ofthe chamber 90 during a milking operation, from the milk inlet 62 to themilk outlet 64.

The lower housing 70 also defines one or more (preferably threelaterally spaced apart) holes 92 to vent from the chamber 90 toatmosphere. The holes 92 should be large enough to ensure adequatedrainage and venting. The holes 92 are depicted as being on a downstreamside of the lower housing 70, but can be other places as well.Positioning the holes 92, as depicted, on the downstream side of thelower housing 70 prevents alignment with piston holes that are used todispense backflushing fluids.

Disposed in the lowermost portion of the chamber 90 is a seal insert 94.(See FIGS. 10A and 10B) In a preferred embodiment, the seal insert 94includes an upper ring-shaped portion 96 and a lower u-shaped portion98. The upper ring-shaped portion 96 and lower u-shaped portion 98 arepreferably formed as an integral unit made of silicone or otherelastomeric material such as (EPDM), but they could be separate seals,if desired.

The upper ring-shaped portion 96 is disposed against an interior chamber90 surface, and is preferably supported by a seat 102 f (FIGS. 9G and9H) formed in the interior of the lower housing 70. When in the milkingposition, the upper ring-shaped portion 96 forms a seal with a lowerportion of the backflush piston 120 to seal the milk flow outlet 64 frombackflushing and dip valve components. See FIGS. 9A and 9G, for example.

The lower u-shaped portion 98 of the seal insert 94 is disposedtransversely to the flow of milk from the milk inlet 62 to the milkoutlet 64. As best seen in FIGS. 9G and 10B, an interior surface of thelower u-shaped portion 98 includes an upstream flange 104 and adownstream flange 106 joined to and spaced apart by a web 108. The loweru-shaped portion 98 can be supported by a mating recess in the lowerhousing 70 chamber 90 wall (FIG. 9E). The functions of these componentsare explained in detail below in connection with the operation of thebackflush piston 120, but the space defined between the upstream flange104, the downstream flange 106, the web 108, the backflush piston 120,and necked-down portion 130 (when in the backflush position) is a ventthat communicates with one or more of the vent holes 92 to provide adouble seal or “block” and a space between for “bleeding” to atmosphere.

In addition, the use of seal flanges 104 and 106 as the only contactwith the backflush piston 120 reduces sticking to one another in a waythat would impede operation. Also, debris such as bedding material,dirt, and sand that moves through the milker unit 40 is less likely toprevent the backflush piston 120 forming a seal with the seal insert 94.It also provides clearance for the backflush piston 120 which helpsreduce damage to the backflush piston 120.

The seal insert 94 is preferably secured to the lower housing 70 with ascrew 109 and a reinforcing plate 110, which is preferably moldedintegrally with the seal insert 94.

Referring to FIGS. 9A-E, disposed in the lower housing 70 chamber 90, isthe backflush piston 120. The backflush piston 120 is sized and shapedto move up and down (in the illustrated orientation) between a milkingposition (FIGS. 9A and C) and a backflushing position (FIG. 9B, 9D and9E). The backflushing piston 120 operates during both backflushing anddipping operations, so its name and lower position are to be understoodas generic terms for a piston and a closed position, respectively. Asseen in FIGS. 11A to 11C, the backflush piston 120 is substantiallycylindrically shaped, but it can have other cross-sectional shapes toensure that it is inserted into the chamber 90 with the properorientation, for example. Also preferably, the backflush piston 120 isclosed at its lower end 122, open at its upper end 124, and has a flange126 extending radially outwardly from its upper end 124. The flange 126has gaps 128 to permit cleaning solution to flow past for enhancedcleaning of the seal.

Essentially, the backflush piston 120 is used to divide the chamber 90and seal the portion above from the portion below and to at leastpartially define a flow path for backflushing fluids into the milkerunit 40. Also, the backflush piston 120 is in the backflushing positionwhen applying teat dip and when backflushing, but not when the safetyvalve 60 is self-cleaning.

As best seen in FIGS. 11A to 11C, the backflush piston 120 has anexterior shape that includes an annular necked-down portion 130 adjacentto the flange 126. The necked-down portion 130 preferably has an outsidediameter that is smaller than the outside diameter of the lower portionof the backflush piston 120, and extends at least partially around thebackflush piston 120.

The exterior surface of the backflush piston 120 further includes twopiston by-pass vents 134 on opposite sides of the backflush piston 120.The piston by-pass vents 134 are essentially indented portions arrangedtransversely to the milk flow path from the milk inlet 62 to the milkoutlet 64, and are positioned high enough on the backflush piston 120 sothat a lower portion of the backflush piston 120 can mate and seal withthe upper ring-shaped portion 96 of the seal insert 94 when in themilking position, and mate and seal with upstream and downstream flanges104 and 106 of the lower u-shaped portion of the seal insert 94. Theby-pass vents 134 do not seal with the upper ring-shaped portion 96 whenin the backflush piston 120 is in the backflush position. Thisarrangement provides a vent for the chamber 90 to bleed off differentialpressure.

Next, the backflush piston 120 includes one or more (preferably twolaterally spaced) holes 138 oriented radially to the backflush piston120. The holes 138 are formed or machined into the backflush piston 120so that they are directed toward the milk inlet 62 when the backflushpiston 120 is in the backflushing (lowered) position (FIGS. 9B and 9D),and are above the upper ring-shaped portion 96 of the seal insert 94when the backflushing piston 120 is in a milking (raised) position (FIG.9A). With this arrangement, the holes 138 are sealed from the milksupply by the upper-ring shaped portion 96 of the seal insert 94.

As best seen in FIG. 11C, inside the backflush piston 120, and adjacentto, but not blocking the holes 138, are two longitudinally oriented andinwardly extending flow vanes 142 that ensure that the backflush fluidsflow through the holes 138 in a desired direction. The flow direction istypically selected based on the shape and/or configuration of the milkercollection bowl 44 of the milker unit 40. This arrangement permits thebackflush piston 120 to be part of a backflush fluid conduit thatextends through the safety valve 60.

Also formed on the interior surface of the backflush piston 120 are twopairs of longitudinally and inwardly extending key ribs 144 (FIGS. 11Aand 11C). Each pair of key ribs 144 is disposed opposite the other. Whenthe backflush piston 120 is disposed in the lower housing 70, the keyribs 144 are arranged on interior sides of the backflush piston 120 thatare transverse to the direction of milk flow, and slidably engage anupwardly extending connector 160, described below.

Disposed in the lower housing 70 chamber 90 between the seal insert's 94interior surface and an underside of the flange 126 of the backflushpiston 120, is a piston return spring 150. The piston return spring 150acts between the flange 126 of the backflush piston 120 and the upperring-shaped portion 96 of the seal insert 94. Preferably, a metal ring152 is positioned between the piston return spring 150 and the top ofthe upper ring-shaped portion 96 of the seal insert 94 to transferspring loads without undue pressure or abrasion on the seal insert 94.

The piston return spring 150 is arranged to bias the backflush piston120 upward toward the milking position (FIGS. 9A and 9C). The pistonreturn spring 150 can be made of metal, plastic or other material, andpreferably has just enough force that can move the backflush piston 120over friction with the seal insert 94, but can be overcome bypressurized air to move the backflush piston 120 downward. The pistonreturn spring 150 and the other springs described herein can be any typeof biasing device.

To compress the piston return spring 150 and move the backflush piston120 toward the backflush position (FIGS. 9B and 9D), compressed gas,such as air, is fed into the safety valve 60, via an air inlet 184,which applies pressure to a backflush operation plate 230 (described indetail below) that, in turn, applies pressure to the backflush piston120. The piston return spring 150 is designed to yield to the pressureexerted by the compressed pressurized air/gas, but to also quicklyreturn the backflushing piston 120 to the milking position (FIGS. 9A and9C).

Also as stated, the backflush operation plate 230 transmits air pressureto the backflush piston 120, when the pressurized gas is vented orremoved by the piston spring 150. One embodiment of a backflushoperation plate 230 in accordance with the present invention isillustrated in FIGS. 12A and 12B has a central opening 231 positionedaround a central shaft 198 of the upper housing 74. The backflushoperation plate 230 is essentially a disk defining a recess 238 forreceiving the lip 239 of the top of the backflush piston 120 so that thebackflush piston flange 126 is in bearing contact with a lower rim 242of the backflush operation plate 230.

An outer u-cup seal 234 (FIGS. 12A and 12B) fits on a mating seat 244 ofthe backflush operation plate 230. Alternatively, the u-cup seal 234could be replaced with a seal formed integrally with the backflushoperation plate 230. The outer u-cup seal 234 extends radially outwardlyfrom the outer diameter of the backflush operation plate 230 for slidingand sealing engagement with the inner surface of the lower housing 70.An inner stem seal 236 is disposed in an inner annular recess 246 on thebackflush operation plate 230 and extends inwardly to be in sliding andsealing engagement with the upper housing central shaft 198.

When in the milking position, pressurized air can flow from the airinlet 184 of the upper housing 74 to force the backflush operation plate230 downward against the force of the piston return spring 150, and movethe backflush piston 120 into the backflushing position (FIG. 9B, 9C,and 9D), while also preventing backflush fluids from flowing upward intothe upper housing 74.

A second embodiment of a backflush operation plate 230 is illustrated inFIGS. 9A, 9B, 12C and 12D, and has a central opening 231 and a recess238 for receiving the lip 239 of the backflush piston 120. Reinforcingribs 233 are formed above and below a wall 232.

This embodiment of the backflush operation plate 230 includes integrallymolded seals 235 and 237 around the outer annular surface and anintegrally molded seal 239 and 241 around the inner annular surface.This design is less costly, requires fewer parts, and is easier toassemble and replace.

The upper seals 235 and 239 seal air pressure to move the backflushpiston 120 into a backflush position. The lower seals 237 and 241 wipedirt and debris from mating surfaces when moving to the backflushingposition, and seal out water during a self-cleaning cycle.

Extending though the central opening 231 of the backflush operationplate 230, is a central shaft 198 of the upper housing 74 (described indetail below). Extending through the central shaft 162, is a connector162 that engages the backflush piston 120 with the dip valve piston 268.As illustrated in FIG. 13, the connector 160 includes a central shaft162, a shaft key 164 at the top of the central shaft 162, and a pair oftabs 166. The shaft key 164 joins to the dip valve piston 268 and theshaft tabs 166 to slidably fit into the piston connection rib pairs 144formed on the inside of the backflush piston 120. This allows fordifferential movement between the dip valve piston 268 and the backflushpiston 120. The bottom of the connector 160 bears on the inside of thelower end 122 of the backflush piston 120.

When pressurized air is applied to move the backflush piston 120downward, the connector 160 is not pulled down because of their slidingrelationship, as described above. Instead, the backflush operation plate230 continues to move down even after the backflush piston 120 engagesand slightly compresses the seal insert flanges 104 and 106 to close offthe milk passage. This additional downward movement results in thebackflush operation plate 230 engaging the tops 169 of the connectortabs 166 to force the connector 160 downward. When the connector 160moves downward, the dip valve piston 268 is pulled down to open the dipvalve piston 268 due to the fixed connection between the two to releasedip.

The sequence of the differential movement between the backflush piston120 and the dip valve piston 268 ensures that the backflush piston 120has sealed off the milk line before any possibility of the dip valvepiston 268 opening. In addition, the backflush piston 120 requires arelatively large movement to close off the milk passage, but the dipvalve piston 268 needs to move only a relatively small amount to open.For example, the backflush piston 120 moves about .75 inches, and thedip valve piston 268 moves about .15 inches. This differential movementis not absolutely necessary, but it reduces the overall height of thesafety valve 60, and provides to above-described safety factors.

The connector tabs 166 upper portions are spaced radially apart from thecentral shaft 198 so that when the connector 160 is in a milkingposition, the tabs 166 will not engage the central shaft 198 of theupper housing 74.

When dipping and backflushing operations are finished, air pressureapplied to the backflush operation plate 230 is released, and the dipvalve spring 326 (explained in more detail below) urges the dip valvepiston 268 (upward as seen in the figures). Due to their slidingrelationship, the connector 160 does not pull the backflush piston 120back up. Instead, the sliding relationship between the connector 160 andthe backflush piston 120 leaves only the piston return spring 150 tourge the backflushing piston 120 back to a milking position, and whenthe backflush piston 120 approaches the top of its movement, it canengage the connector 160 to provide a redundant force against the dipvalve piston 268.

The central shaft 162 of the connector 160 defines a longitudinalchannel 168 through which backflushing fluid flows down, into thebackflush piston 120, and out the backflush piston 120 holes 138. Alower end of the longitudinal channel 168 also mates with the flow vanes142 in the backflush piston 120 to define a backflush fluid conduit forflow efficiency.

The central shaft 162 also defines a slot 172 in an upper portion of thecentral shaft 162 through which cleaning fluid flows during backflushingand self-cleaning.

The connector 160 extends upward, out of the lower housing 70, and intothe upper housing 74 for connection to components described below.

Upper Housing

As depicted in FIGS. 9A through 14A, for example, the upper housing 74preferably includes connecting shafts 180, two air inlets 184, 185, abackflush inlet 186, a teat dip inlet 188, a teat dip outlet 190, and aguard 192 for protecting the inlets from damage.

The air inlet 184 enters the upper housing 74 and turns downward (FIG.14B) to operate the safety valve 60 by acting on the backflush operationplate 230, and it is connected via a hose or other suitable fluidcommunication device to valve 611 and outlet 615 on the valve block 610(FIGS. 6A to 6D). Air through the air inlet 185 enters the upper housing74, turns upward and through an umbrella valve 253 a (FIG. 14D) to“slug” dip and other fluids through the safety valve 60, related dipdelivery tubes, and chambers. The air inlet 185 is in communication withthe air chase outlet 446 on the dosage valve 84. The backflush inlet 186is in fluid communication with valve block outlet 637 on the valve block610 to feed backflush fluid, water, and air to the safety valve 60. Thebackflush inlet 186 enters the upper housing 74 and the flow is divertedinto two paths. One flow path turns upward and enters through umbrellavalve 253 b to clean the dip components. The other flow path extendsinto the central shaft 198 and then flows down to clean the safety valve60 and milker unit 40. The dip inlet 188 is in communication with thedosage valve outlet 438, and enters the upper housing 74 where it turnsup through umbrella valve 253 c. The rest of the dip flow path isdescribed below.

Generally, the interior of the upper housing 74 defines a longitudinallyextending air conduit in the hollow central shaft 198, a backflushchamber 200, a dip inlet chamber 204, and a dip outlet chamber 206. Atransverse wall 210 divides the upper housing 74 and at least partiallyforms some of the chambers 200, 204, 206.

Like the lower housing 70, the upper housing 74 is preferably made ofthe same translucent plastic described above for the upper housing 74,and for the same reasons. The upper housing 74 is sized and shaped tomate with and be connected to the lower housing 70, preferably usingscrews 78, bolts, and/or bushings, but they can also be formedintegrally with one another. A ring seal 214 is provided in an annularrecess formed in the lower end of the upper housing 74 to seal theinterface between the lower housing 70 and the upper housing 74.

As best seen in FIG. 14B, the first air inlet 184 communicates with theair conduit in the central shaft 198 to feed compressed air against thebackflush operation plate 230 and into the lower housing 70 to force thebackflush piston 120 into the backflushing position (FIGS. 9B).

As depicted in FIGS. 14C and 14D, the second air inlet 185 is incommunication with the dip inlet chamber 204 via a hole 218 to providepressurized air from the dosage valve 84 outlet 446 that purges cleaningfluids from the safety valve 60 and any related hoses, lines, and dipmanifold, liner mouth piece (lipped portion in liner head), and dipchannels.

The backflush inlet 186 extends radially inwardly to the upper housing74 and communicates with the central shaft 198 and the longitudinalchannel 168 in the connector 160 (see FIG. 13) to supply backflush fluidto the backflush piston 120, and out of the backflush piston holes 138.Preferably, the backflush inlet 186 is arranged asymmetrically (slightlytangential) to the central shaft 198 to allow for adequate connectionspace for all of the hoses and to generate some beneficial cleaningturbulence when the safety valve 60 is cleaning itself

As seen in FIG. 14F, the dip inlet 188 extends into the upper housing 74and turns upwardly through a third opening 224 into the dip inletchamber 204.

As described above, there is a backflush operation plate 230 that actsto move the backflush piston 120 down. The backflush operation plate 230is disposed in the lower housing 70, but slides on the central shaft 198of the upper housing 74 because the central shaft 198 extends downwardinto the lower housing 70.

Should the safety valve 60 only be used for backflushing or washinganimal teats, there is only a need for the above-described items, andthe cap 76 mates with the upper housing 74 and the safety valve 60functions to seal and backflush the milker unit 40. If teat dipapplication functions are desired, the items described below areincluded.

Dip Valve Components

When teat dipping is used as an option, FIGS. 14E, 14F, 15, 16A, 16B,16C, and 16D for example, show that the safety valve 60 have in itsupper housing 74 dip valve components that include; the dip inlet 188,the dip outlet 190, the dip inlet chamber 204, the dip outlet chamber208, as well as the elements described below. The dip inlet 188 isconnected by a hose to be in fluid communication with the dosage valveoutlet 438, and the dip outlet 190 is connected to a dip deliverychannel (described below). The safety valve 60 includes a top plate 262,a top plate seal 264, a dip valve piston 268 disposed in the top plate262 for sliding movement between a dip position (down as viewed in FIG.14F and a milking position (up as viewed in FIG. 9A), and a dip pistonseal 270.

The backflush inlet 186, the dip inlet 188, and the second air inlet 185are each closed with flexible valves 253 a, 253 b and 253 c that arepreferably an “umbrella valve” made of silicone, and connected togetherat 254 for ease of manufacture and installation. (See: FIG. 17) Thevalves 253 a-c are one-way valves that are opened by air, water, or dippressure to allow air, water, or dip to enter, but the valves 253 a-crestrict flow in the opposition direction because the valves 253 a-c areresilient and close when there is no dip, air or water pressure to keepthem open. The valves essentially function as suction cups when nopressure is there to open them. Also, pressure from other fluidsentering other valves contributes to keeping the valves 253 a-c closed.

As depicted in FIGS. 16A to 16D, the top plate 262 includes acylindrical cup portion 272 with a transverse bottom wall 273 forslidably receiving the dip valve piston 268. The top plate 262 alsoincludes fastening tabs 274 through which screws 78 can extend to fastenthe top plate 262 to the top of the upper safety valve housing 74. Thetop plate 262 includes an outer annular seat 276 on which the cap 76 ispositioned. The top plate 262 can be made of any suitable materialincluding Radel R5000, other plastic or stainless steel. The materialsused for the various parts of the safety valve 60 are preferably thesame or at least have similar properties such as coefficient of thermalexpansion and chemical resistance.

The top plate 262 and the top plate seal 264 are preferably formedtogether to reduce expense, avoid an assembly step, and to ensurealignment of the various holes. Alternatively, aligning these parts canbe done with two seal alignment pins extending downward from the topplate 262 that are preferably of a different shape and/or orientationand/or spacing from one another and other functional components.Regardless of which method is used, the seals 324 and 325 must matchwith holes 288 and 289 in the bottom wall 273.

In the bottom wall 273 of the top plate 262 there is an upstream dipopening 288, a downstream dip opening 289, and a central opening 290through which the connector 160 extends for connection to the dip valvepiston 268.

Inside the cylindrical cup portion 272 of the top plate 262 and the topsurface 294 of the bottom wall 273 defines a dip flow channel 296 withthe bottom on the dip valve piston 268. An additional recess can beformed in any of these surfaces to help control dip flow, but the spacebetween the dip valve piston 268 and the top surface 294 of the bottomwall 273 is adequate between 312 and top 262. The dip flow channel 296can be any shape that provides efficient flow characteristics for dip,with the dip flow channel 296 extending between the dip openings 288 and289. Dip flows up through the upstream dip opening 288, across and downthrough the downstream dip opening 289.

The dip valve piston 268 is depicted in FIGS. 9F, 14C, 14F and 15, andis sized to be slidably disposed in the top plate 262 cylindrical cupportion 272, and includes a head 298 defining an outer annular sealrecess 300 with a seal 301, a central connector post 302 extendingdownward, a downwardly extending upstream dip valve pin 304, adownwardly extending downstream dip valve pin 305, a number of notches308 that provides better rinsing of u-cup, and a grab point forassembly, an upper recess portion 310, and a bifurcated post 312 thatextends upward above the surface of the head 298 to form a stop. Thepost 312 is also preferably bifurcated for improved fluid flow forcleaning.

The central connector post 302 of the dip valve piston 268 is hollow andincludes at its lower end a receptacle 316 that mates with the connector160 preferably in a snap relationship. The receptacle 316 is open at oneside and to receive the top end of the connector 160 by engaging aconnector slot 318.

A dip valve spring 326 (FIG. 9E) is disposed in the central shaft 198 ofthe upper housing 74 and is prevented from extending downward and out ofthe central shaft 198 by one or more spring seats 328. The dip valvespring 326 is also positioned around the central shaft 162 of theconnector 160 to bias the connector 160 and the dip valve piston 268(upward) toward a milking position.

The backflush piston return spring 150 biases the backflush piston 120upward and the dip valve spring 326 biases the dip valve piston 268upward despite the use of the connector 160 joining these two pistons150, 268. The force of two springs 150, 326 is not necessary to move thepistons 150, 268 upward, but they provide a redundancy that ensures safeoperation of the safety valve 60.

The dip valve pins 304, 305 each include a stem 320 and a valve head322. The valve heads 322 are sized and shaped to substantially close andseal the dip openings 288 and 289 (with seals 324 and 325) in the bottomwall 273 of the top plate 262 when the dip valve piston 268 is in themilking (or closed) position (FIGS. 9A and 9C).

The dip openings 288 and 289 are sealed when the dip valve piston 268 isclosed. On opposite sides of these seals, there may be differentialpressures that could cause dip to seep past the seals 324 and 325.Accordingly, a vent between the dip openings 288 and 289 and seals 324and 325 is provided for the desired block-bleed-block feature thatensures safe operation of the invention.

To provide a suitable vent, there is a skirt 277 extending downward fromthe bottom wall 273 of the top plate 262. The plate seal 264 is disposedwithin the skirt 277. Formed in both the plate seal 264 and/or the skirt277 are two slotted vents 282 that extend radially outwardly andvent/bleed to atmosphere at vent holes 279. The slotted vents 282 andvent holes 279 are positioned between the upstream dip opening 288 andthe downstream dip opening 289 to provide a block-bleed-blockarrangement.

As seen in FIG. 9F, two dip hole seals 324 and 325 enhance the sealbetween the dip openings 288 and 289 and the dip valve heads 322, andprovide initial and secondary seals or “blocks” In between the seals 324and 325, the top plate 262 is vented in two places. The first vent is B5that passes down and past the dip piston post 302 to vent/bleed the topplate 262 out of the lower housing vents 92 described above. The secondvent is B6 that vents upward and out of the cap 76 vents 334. Thus, theblocks 324 and 325 are spaced apart with two bleeds B5 and B6 disposedin between to provide important block-bleed-block functions.

When the dip valve piston 268 is in the dipping position (FIG. 14F), thedip valve heads 322 move downward and no longer seal the dip openings288 and 289 because the stems 320 of the dip valve pins 304 are smallerthan the dip openings 288 and define annular openings through which dipflows. Dip flows up through the upstream dip openings 288, across to theother side, and down through the downstream dip opening 289.

Safety Valve Cap

The cap 76 of the safety valve 60 is best depicted in FIG. 18. The cap76 is cup-shaped with four screw holes 330 for securing the cap 76 tothe other portions of the safety valve 60. Preferably, the cap 76 ismade of a translucent plastic, such as Radel R5000 for the reasonsstated above.

The cap 76 also includes a pair of cap vents 334 that are formed by gaps336 in the cap 76 and vent hoods 338. The vent hoods 338 extenddownwardly from the cap 76 and ensure that the cap 76 is vented toatmospheric pressure.

A bottom edge 332 of the cap 76 rests on the top plate 262 of the dipsafety valve 260 when present or onto the upper housing 74 when the dipsafety valve 260 is not included. No seal is needed between the bottomedge 332 of the cap 76. The cap 76 preferably includes an interior key339 (FIG. 18) that mates with a key-way on the upper housing 74 toensure proper alignment and orientation of the vents 334.

Safety Valve Operation

As stated above, the safety valve 60 must move between a milkingposition (FIG. 9A) and a backflushing position (FIG. 9B) to preventcontamination of the milk supply by the teat dip or backflushing fluids.Due to pressure differentials on opposite sides of the safety valve 60,it is desirable to do more than simply seal off chemical, air, or otherfluid lines from the milk supply.

With the present invention, the pressure differential on each end of thesafety valve 60 is avoided with vents exposed to atmospheric pressure to“bleed” off any pressure differential that may cause unwanted seepagepast a seal. In this manner, pressures on each side of the safety valve60 are isolated from one another and seepage of chemicals, air, andother fluids into the long milk tube and milk supply is prevented.Generally, seals are provided in pairs with a vent to atmospheredisposed between the seals of each pair. This arrangement provides a“block-bleed-block” function to ensure that fluid that seeps past oneseal cannot seep past the other seal.

As seen in FIG. 9C, to achieve the “block-bleed-block” function when thesafety valve 60 is in the milking position (FIGS. 9A and 9C), a block isformed by the seal insert 94, and specifically by the upper ring-shapedpart 96 of the seal insert 94. The upper ring-shaped part 96 seals anannular gap between the interior surface of the chamber 90 and a lowercylindrical portion of the backflush piston 120.

The bleed function in the milking position (FIGS. 9A and 9C) isperformed by two different paths between the safety valve chamber 90 andthe atmosphere outside of the safety valve 60 and the milker unit 40. Itis only necessary to have one such “bleed” path, but the illustratedembodiment provides a bleed redundancy for added safety.

The first bleed path is illustrated in FIG. 9C and is designated as B1.This first bleed path B1 is a path from the chamber 90 through backflushpiston holes 138, and through holes 92 in the lower housing 70. Thesecond bleed path B2 is from the chamber 90 of lower housing 70 througha space between the central connector post 302 of the dip safety valvepiston 268 and central opening 290 of the top plate 262, through thecylinder 272 of the top plate 262, past the outer annular seat 276 ofthe dip valve piston 268, up into an interior portion of the safetyvalve cap 76, and out cap vents 334. The second line of “block” functionis performed by seals in the valve block 610 that controls the flow ofbackflushing fluids, air, water and teat dip into the safety valve 60.Also, the valve block 110 includes a block-bleed-block feature, asdescribed above as a redundant safety feature.

As seen in FIGS. 9B, 9D, and 9E, the safety valve 60 is in thebackflushing position with the backflush piston 120 in its lowermostposition with a lower surface of the backflush piston 120 engaging theu-shaped 98 portion of the seal insert 94. More specifically, the lowersurface of the backflush piston 120 is in contact with the upstreamflange 104 and the downstream flange 106 of the u-shaped 98 portion ofthe seal insert 94. This arrangement provides a double block between thesafety valve 60, milk inlet 62, and milk outlet 64.

Between the upstream flange 104 and the downstream flange 106 is the web108 of the seal insert 94. The web 108 is spaced apart from the lowersurface of the backflush piston 120 to define part of a “bleed” path B3(FIG. 9E) that by-passes the upper portion of the backflush valve 120and the upper ring-shaped portion 96 of the seal insert 94 through thepiston by-pass vents 134, and through the holes 92 in the lower housing70. This block-bleed-block arrangement prevents backflushing fluid andteat dip from entering the milk supply because any seepage past eitherseal will drain through the gap 111, which is a bleed path. (FIG. 9E).

The teat dip block-bleed-block function is performed by the upstream dipvalve pin 304 in connection with a dip opening 288 in the top plate 262,and the corresponding dip hole seal 324 of the top plate seal 264. Asecond block is formed by the downstream dip valve pin 305 in connectionwith a dip opening 288 in the top plate 262 and the corresponding diphole seal 324 of the top plate seal 264.

In this arrangement, there are at least two bleed paths. Bleed path B5in FIG. 9F is defined by a space between the dip valve piston 268 andthe interior portion of the top plate 262 cylindrical cup portion 272.B5 is further defined by a space between the dip piston centralconnector post 302 and the central opening 290 of the top plate 262, thelower housing chamber 90, and the three openings 220, 222, and 224.

Another bleed path B6 (FIG. 9F) is defined by the space between the dipvalve piston 268 and the interior portion of the top plate cylindricalcup portion 272, upward into the cap 76 and out of the cap vent hoods338.

Yet another bleed path is formed in the valve block housing 613 by thespool 621, so that differential pressure cannot pass the valves and intoany of the feed lines to the safety valve 120.

When it is desired to apply teat dip, the dip safety valve 260 isoperated by compressed gas such as air or other suitable fluid,mechanical device or electrical device to move the dip valve piston 268downward against the force of the dip valve return spring 326 so thatthe dip valve pins 304 and 305 no longer seal the dip valve holes 288,289.

As seen in FIGS. 14A and 14E, teat dip is pushed through the dip inlet188 in the upper housing 74. The dip flows under pressure through thedip inlet chamber 204, up through upstream dip hole 288, through theflow channel 238, through the downstream dip hole 289, through the dipoutlet chamber 208, out through the dip outlet 190, through tube 345joined to the dip outlet 190 with an elbow 580 and toward the dipmanifold 170.

When backflushing fluid (such as wash chemicals, rinse chemicals, water,and/or air) are to be pumped from the safety valve 60 upstream into themilker unit 40, the following operation takes place. It should beunderstood that during a backflush operation, the milker unit 40 willnot be upright as illustrated in most of the drawings. Instead, themilker unit 40 will be upside down or at some generally downward angle,and hanging from a detacher mechanism as in FIG. 4B. This position aidsin draining backflush liquids from the milker unit 40 in addition to afinal “air slug” that is pumped through the safety valve 60 and themilker unit 40.

Backflushing fluid enters the upper housing 74 backflush inlet 186, downthrough the central stem 168, down through the backflush piston 120, outof the holes 138 in the backflush piston 120 and “upstream” through themilk inlet 62 and into the milker unit 40. The safety valve componentsas described define a backflush fluid conduit extending through thesafety valve 60 between the backflush fluid inlet 186 and the milk inlet62.

When desired to clean and rinse the safety valve 60, there can bealternating pulses of air and water for any desired number of sequencesafter the backflushing piston 120 returns to the milking position.Preferably, there are more than one pulse of both air and water toprovide agitation, and efficient and thorough cleaning. Water used inrinsing the safety valve 60 also lubricates the seals for less frictionand resistance in moving the various pistons and valves. For thisreason, it is also desirable to wash or rinse the safety valve 60 priorto start-up.

Also, it is preferred to clean the safety valve 60 with the backflushpiston 120 in its milking position because some milk may enter the bleedarea next to the backflush piston 120 when the backflush piston 120 isin the upper position. This will clean backflush chemicals, teat dips,and residual milk from the safety valve 60. This process is doneautomatically by blowing water and air through the safety valve 60before attaching the milker unit 40 to another animal.

FIGS. 22 through 25 are Control Operation charts that illustrate asequence of all the various elements that take place in a typical singlecycle of the safety valve 60. FIGS. 22, 23, and 24 are each a portion ofa complete backflush and dip application cycle. FIG. 22 is a dipping andbackflushing portion of the cycle, FIG. 23 identifies additional stepsin the backflush operation, and FIG. 24 shows the steps of a dosingvalve recharged in preparation for the next dipping procedure. (Theabbreviation “BF” in the charts refers to backflush.) From the end ofmilking, closing off the milk line, dipping a cow, backflushing themilker unit, and self-cleaning of the safety valve, to being ready for anext milking operation is about forty-five seconds, in the preferredembodiment. FIG. 25 illustrates steps in the system 20 operation and thefunction the each step serves.

Dip Manifold

A teat dip manifold 170 is preferably included to separate the dip doseinto four substantially equal quantities. The dip manifold 170 alsoisolates vacuum in each liner head 172 from vacuum in other liner heads172 (See FIGS. 19A-E). Preferably, a four quarter milker unit systemincludes a backflushing safety valve 60 pre-assembled to the milker unit40. When adding the dipping function to an existing system, the dipmanifold 170 can be secured to a four quarter milker unit 40 with an airdivider 174, which is part of a liner securing device or it can beloosely attached in any convenient location. In the embodiment of FIG.1A, the manifold 834 is mounted on the milker unit collection bowl 844.

Two manifold designs are shown in FIGS. 19A-E and 19F-H respectively Theprimary functions in both embodiments are to prevent air flow from oneteat cup 48 to the other during milking, and provide even distributionof dip to all teats, and to distribute substantially even volumes of dipto each teat.

The manifold 540 depicted in FIGS. 19A-E includes a base 542, a cover544, alignment pins 546 in the base 542, four outlets 550, one inlet552, a bladder seal 554, and outlet guards 556.

The base 542 and cover 544 are preferably molded from plastic, but couldbe any suitable material. They are assembled by aligning the alignmentpins 546 of the base 542 with recesses in the cover 544. The base 542and the cover 544 are joined by welding, adhesive, or mechanicalfastener.

As seen in FIGS. 19A through 19E, the base 542 includes a manifoldchannel 560 in fluid communication between the inlet 552 and the fouroutlets 550. The manifold channel 560 in FIGS. 19C and 19D is preferablybifurcated adjacent to the inlet 552 to divert dip flow to each side ofthe manifold 540, and then bifurcated again at each side of the manifold540 for a total of four substantially equal doses of dip to flow throughcorresponding outlets 550.

The alternate manifold channel 560 illustrated in FIGS. 19F and 19G isalso bifurcated adjacent to the inlet 552, but in this embodiment, thereis no other bifurcation in the flow channel 560. Other flow channeldesigns are also possible.

The base 542 further includes mounting tabs 564 (FIG. 14) that are usedto join the manifold 540 to any suitable location. Other mountingmethods are also possible.

The manifold 540 also includes the flexible bladder 554 made of siliconeor other elastomer, and disposed between the base 542 and the cover 544to seal the interface between the two, but to also serve as a checkvalve for individual outlets 550. The bladder 554 includes alignmentholes 570 to ensure proper alignment with the base 542 and cover 544during assembly, and is joined to the base 542 with screws 545 or othersuitable fasteners.

The bladder 554 includes flexible vacuum isolation diaphragm seals 576each of which is disposed in the channel 550 adjacent to a correspondingoutlet 550 so that flow through the outlet 550 is possible in only onedirection. This arrangement of bladder vacuum isolation diaphragm seals576 adjacent to the outlets 550 blocks pressure differentials inindividual dip outlets 550 from adversely affecting dip flow throughother dip channels 550.

The manifold 540 depicted in FIGS. 19A through 19E has four independentdiaphragm seals 576 that each seal a separate outlet 550. The manifold540 depicted in FIGS. 19F and 19G has two independently operatingdiaphragm seals 576 that each seal a pair of outlets 550. In bothembodiments, the seal channel 560 is sized and shaped to receive amatching diaphragm seal 576, which are preferably formed as embossmentson the bladder 554.

Each of the two vacuum isolation diaphragm seals 576 includes a pair ofdip outlets to prevent pressure differentials between pairs of dipoutlets 550 from affecting dip flow through neighboring pairs of dipoutlets 550.

Dip flows into the manifold 540, through the inlet 552, the manifoldchannel 560, and urges the diaphragm seals 576 upward against theirnatural bias toward a closed position. Once the diaphragm seals 576 areopen, dip flows out individual outlets 550.

The base dip inlet 552, preferably has joined to or molded integrallywith it, a widened portion 580 to provide a gripping surface whenattaching and detaching a hose, for example.

Shell for Internal Dip Channel

Illustrated in FIG. 15 is an external teat dip delivery tube fordelivering dip to the liner is to pass the dip tube up along the insideof the teat cup 48.

Illustrated in FIGS. 16 to 19 is an internal teat dip delivery tube 190that is disposed inside of a teat cup 48. The delivery tube 190 can besecured to the interior wall of the teat cup 48 or it may simply extendthrough the teat cup 48 with no connections.

Depicted in FIGS. 20A and 20B, are teat cup assemblies 700 for use withthe present invention or separately with other dip delivery systems. Theteat cup assemblies generally include a shell 702 and liner 704. Theliner 704 can be the type disclosed in application Ser. No. 12/157,924which is incorporated herein by reference. The shell 702 is preferably astainless sleeve with a TPR (thermal plastic rubber) bottom end or cap734. Stainless is preferred for the shell 702, but molded (clear,translucent or opaque) plastic or other materials can be used, making ita very simple molded part that could include a dip channel 708 withinthe shell 702. This embodiment of the teat cup assembly is preferredbecause it is easier to manufacture, since the cap will be a simpleinjection molded piece with no welding required. Nonetheless, other teatcup assemblies can be used with the other components of the presentinvention.

The shell 702 is a simple tube. The only welding will be to tack weldthe dip delivery channel 708 onto the inside, as illustrated or outsidein an alternate embodiment described below. The dip delivery channel iswell protected from top to bottom, making the teat cup assembly 700 veryrobust. The dip channel 708 connects a liner fitting 720 to transmit dipto an internal dome in the liner. In FIG. 20A, the liner fitting 720extends outside of the liner head 722, and in FIG. 20 B, the linerfitting 720 is inside the liner head 722. These two options providedifferent assembly methods and visibility while assembling the parts.

Positive keying of the liner 704 to the shell 702 is provided by twoslots 712 and 714, one for the dip tube connection and one to forceproper alignment, enabling the dip channel 708 connection. Additionalholes 716 will be used as snaps to help hold the liner head 722 onto theshell 702 as cows may step on it.

A nipple 730 on the bottom of the shell 702 connects to a dip deliverytube or a connection using individual fittings pressed into bosseswithin the TPR can be used to provide flexibility from cow abuse withreduced breakage. The shell 702 is snapped into the cap 734 to provide asolid one-piece feel, making liner 704 change as easy as with a singlepiece shell 702.

With the dip channel 708 on the inside, a triangular, square ormanipulated round liner is preferred, so the liner 704 will not collapseand contact the internal dip channel 708.

Shells for External Dip Channel

FIG. 20C illustrates one embodiment for a dip passage 748 on the outsideof the shell 48. The dip passage 748 connects to the liner 704 when theliner 704 is assembled to the shell 48 in the proper orientation. Thedip passage 748 connects to a liner fitting 724 in a manner similar tothe embodiments of FIGS. 20A and 20B.

FIG. 20D illustrates another embodiment for a dip passage 766 on theoutside of a shell 742. The dip passage 766 connects to the liner 704when the liner 704 is assembled to the shell 48 in the properorientation. The dip passage 766 connects to a liner fitting 764 in amanner similar to the embodiments of FIGS. 20A and 20B. The external dippassage 766 is protected by a rubber, silicone, or other material joinedto the shell. The short milk tube 46 can be integral with the liner 704,and the short milk tube 46 preferably terminates at a knob 770 thatconnects to a milk collection bowl.

Shell Liners

As stated earlier, preferred shell liners for use in the presentinvention are disclosed in U.S. application Ser. No. 12/215,706, whichis incorporated herein by reference. FIGS. 21A, 21B, and 21C depictrepresentative examples of a shell liner 920, from that application.

In FIG. 21A, there is depicted a milker unit liner 920 in accordancewith the present invention. The liner 920 includes a dome 922, a skirt924, a barrel 926, and a delivery channel 928. The skirt 924 extendsdownward from the dome 922 and is spaced away from the barrel 926 todefine a recess 927.

The liner 920 is sized and shaped to fit into a conventional outer shellor “teat cup” (not illustrated) so that the top of the teat cup fits inthe recess 927 between the skirt 924 and the barrel 926, but other shelltypes and alignment aids can be used. This relationship secures theliner 920 to the teat cup and forms a seal for the vacuum. The linerbarrel 926 may have any cross-sectional shape including round,triangular, and square, or any other shape. Alternatively, a liner cancomprise a separate dome and barrel that are connected to each otherdirectly or indirectly using a teat cup or the other suitable device.The present invention is directed to a dome 922 having an inner surfaceto which flow diverters are joined regardless of the type, size, orshape of barrel. The liner 920 can be made of rubber, silicone, or othersuitable materials.

The delivery channel 928 can be formed integrally with the other linercomponents or attached after the liner 920 is formed. The deliverychannel 928 may be any of the design types described above, or it can bea separate component so long as it is attached to the liner 920 to actas a conduit for teat dip or cleaning fluids being introduced into thedome 930 from the safety valve 60.

FIG. 21B illustrates an embodiment of a liner dome 930 in accordancewith the present invention, and that is removed from the other linercomponents and inverted to show an inner surface 932. This dome 930includes a teat opening 934, and an annular recess 936 for mating withthe top of a teat cup (not illustrated).

The liner dome 930 further includes a teat dip distribution structurehaving an inlet 966 (not depicted in FIG. 21B, but see FIG. 21C), afirst flow diverter which is illustrated in this embodiment as a flowbifurcating vane 942, and a second flow diverter which is illustrated asa pair of ridges 944. The inlet 966 is preferably an opening that is thesame diameter as the delivery channel 928, but it can be any size orshape to obtain satisfactory flow characteristics or simply provide easeof manufacturing. The inlet 966 could also include a nozzle in the formof a slit, for example, that is either molded into the dome 930 duringmanufacture or cut into the dome 930 after molding. A slit shape acts asa one-way valve to inhibit the flow of milk, teat dip 967 (FIG. 21C),cleaning fluid, and debris from flowing in the wrong direction throughthe inlet 966.

The inlet 966 can also be a simple opening in the dome 930, and adelivery tube may be used in combination with the inlet 966 so that thedelivery tube defines the flow characteristics or a valve and the inlet966 simply provides an opening through which teat dip passes into thedome 930. Regardless of its shape or size, the inlet 966 is preferablyjoined to the dome 922 by being formed integrally in the liner dome 922,but the inlet 966 can be joined to the dome 922 in any other suitablemanner.

The inlet 966 is connected via the delivery channel 928 to a teat dipsource and/or a backflushing source (not illustrated). In this manner,teat dip 967 (FIG. 21C) is provided through the inlet 966 under pressurefrom a pump, air pressure or other suitable device.

If left to flow directly toward a teat, most of the dip would be appliedto the side of the teat closest to the inlet 966, with some flowpossibly reaching other sides of the teat if the dosage quantity is highenough. It is unlikely in practice that dip would reach all teat sidesand even less likely that teat dip application would be uniform aspreferred.

To redirect the inward and radial flow, the flow bifurcating vane 942 isdisposed adjacent to the inlet 966 and in a flow path defined by theinlet 966. The flow bifurcating vane 942 is shaped to split and redirectthe upward flow from the inlet 966 into a substantially annular flowpath or pattern around the periphery of the dome inner surface 902. Asdepicted, the flow bifurcating vane 942 splits the flow substantiallyevenly in each direction to define a pair of flow paths, but if otherinlets are used or other conditions warrant, the flow could be split inother proportions or simply redirected in a desired flow path.

The inlet 966 preferably defines two ramped and arcuate surfaces 920 onwhich the teat dip flows as it is being redirected. In this embodiment,a raised central portion 922 is used to confine the flow so that teatdip is not flowing directly toward the teat. In alternate embodiments,it is possible to permit some of the flow to be applied directly to theteat without being substantially redirected. In such embodiments, thecentral portion 922 may include openings, slots or ramps through or overwhich teat dip can flow. It is even permissible for some of the dip toflow over the bifurcating vane 912 and directly toward the teat.Further, the arcuate surfaces 950 can be shaped so that teat dip flow isnot directed around the periphery, but instead through a flow pattern orradius that is smaller than the dome chamber's 902 periphery.

The flow ridges 954 preferably have arcuate shapes and contact surfacesthat are joined to the inner surface 902 of the dome 930 and arranged inthe flow path. The flow ridges 954 are shaped and sized to redirect theperipheral teat dip flow inward toward a cow's teat. In a preferredembodiment, the flow ridges 954 have a height dimension that redirectsall the teat dip flowing from the flow bifurcating vane 942. Inalternate embodiments, the height of the flow ridges 954 could bereduced to permit some of the flow to by-pass the flow ridges 954 andflow to the part of the inner surface 902 opposite the flow bifurcatingvane 912 or to other flow diverters (as described below). Further, theflow ridges 914 are depicted as being symmetrical, but they could bedifferent sizes, shapes, positions, or orientations to provideasymmetric flow, if desired.

Most types of teat dip that would be flowing through the dome 930 havean inherent surface tension that helps establish a desired flowcharacteristic by remaining adjacent to the dome 930 surface and to thecow's teat so that the dip will cover areas of the teat that are not inthe direct flow path defined by the flow diverters.

The flow diverters of the present invention are joined to the innersurface of the dome by being molded integrally with the dome, or theymay be joined to the inner surface of the dome with glue or any othersuitable means.

FIG. 21C is an alternate embodiment of the present inventionillustrating a cross-section of an upper portion of a liner 980 having adome 982, a barrel 984, and a teat opening 986. A delivery channel 990is formed integrally with the dome 992. A hose, pipe, or tube (notillustrated) can be joined to the delivery channel 990 as a conduitbetween a source of teat dip and the delivery tube 990, as describedabove. The delivery channel 990 has at its upper end an inlet 966 thatmay be the same diameter of the delivery channel 990 or in the form of anozzle or slit that is either molded into the liner 980 or cut after theliner 980 is molded. Other types of dip applicators can be used in theinvention, but a dome with flow diverters is preferred.

Illustrated in FIG. 21D, is a cross section of a shell 702 with aninternal dip delivery channel 708 and with the liner barrel 780collapsed. Without special precautions, a liner barrel can collapse,make contact with the dip delivery channel 708, and cause premature wearand failure of the liner. With the dip channel 708 on the inside, atriangular, square or manipulated round liner is preferred to controlthe shape orientation of the collapsed barrel, so the liner 704 will notcollapse and contact the internal dip channel 708.

The liner barrel 780 in FIG. 21D is formed, machined or molded withslight variations in wall thickness, such as a relatively thin wall atportions 786 and relatively thick at portions 788, to control collapseof the liner barrel 780 into an oval shape around a longitudinal axis784 that is perpendicular to a transverse axis 786 on which the dipdelivery channel 708 is disposed. This arrangement ensures that theliner barrel 780 does not contact the dip delivery channel 708.Attachment nubs 788 are shown in the head of the liner to secure it tothe shell 702.

Preferably, the difference in wall thickness for the two portions 786,788 is only from about .005 inches to about .010 inches, and is createdby increasing thickness at portion 788. An elliptically machined moldcan be used to create this difference.

The present invention can have many benefits, including but not limitedto, one or more of the following: automate the dipping process toincrease operator efficiency and reduce operator fatigue; provide safe,individual disinfection of the teats to reduce pathogenic organisms onthe teat; prevent transfer of infection from animal to animal, and thusimprovement of udder health of the entire herd; reduce or minimizechemical consumption (as opposed to spray or other automated dippingsystems); improve uniformity of teat dip application; prevent chemicalcontamination of the milk and of the downstream milk system lines;reduce water consumption during backflushing of the milker unit; and beretrofitted to nearly any available milking unit.

The above detailed description is provided for understanding theembodiments described and, unless otherwise stated, is not intended tolimit the following claims.

1. A safety valve for a dairy system component, the safety valvecomprising: a cup defining: a first valve seat, a second valve seat, anda third valve seat; and a valve piston slidably disposed at leastpartially in the cup to move the safety valve between: a closedposition, in which the first valve seat and the second valve seat areclosed, and the third valve seat is open to a vent; and an openposition, in which the first valve seat and the second valve seat areopen to a fluid flow channel between the first valve seat and the secondvalve seat, and the third valve seat is closed to the vent.
 2. Thesafety valve of claim 1, wherein the first valve seat and the secondvalve seat are at least partially defined by openings in a closed end ofthe cup, and the third valve seat is at least partially defined by anopen end portion of the cup.
 3. The safety valve of claim 1, wherein:the valve piston includes a first valve head disposed to engage thefirst valve seat when the safety valve is in the closed position, asecond valve head disposed to engage the second valve seat when thesafety valve is in the closed position, and a third valve surface spacedapart from the third valve seat when the third valve seat is open to thevent.
 4. The safety valve of claim 1, wherein: the third valve seat isat least partially defined by an interior surface of the cup.
 5. Thesafety valve of claim 1, wherein: the cup includes a closed end definingthe first valve seat and the second valve seat, and an open end portiondefining at least a portion of the third valve seat; and the valvepiston includes a first valve head disposed at least partially outsideof the cup when the safety valve is in the open position, a second valvehead disposed at least partially outside of the cup when the safetyvalve is in the open position, and an exterior surface that slidablyengages the third valve seat when the safety valve is in the openposition.
 6. The safety valve of claim 1, wherein: the cup includes aclosed end defining the first valve seat and the second valve seat, andan open end portion at least partially defining the third valve seat;and the valve piston includes a first valve element spaced apart fromthe first valve seat when the safety valve is in the open position, asecond valve element spaced apart from the second valve seat when thesafety valve is in the open position, and a third valve element disposedto engage the third valve seat and substantially close the cup open endportion when the safety valve is in the open position.
 7. The safetyvalve of claim 1, wherein: the cup includes a closed end defining thefirst valve seat and the second valve seat, and an open end portion ofreduced wall thickness defining at least a portion of the third valveseat; and the valve piston includes a first valve element disposed toengage the first valve seat when the safety valve is in the closedposition, and a third valve element disposed to be spaced apart from theopen end portion to open the third valve to the vent.
 8. The safetyvalve of claim 1, and further comprising: a housing defining an inletchamber in fluid communication with the first valve seat, and an outletchamber in fluid communication with the second valve seat when thesafety valve is in the open position.
 9. The safety valve of claim 1,and further comprising: an actuator operatively engaged with the valvepiston.
 10. The safety valve of claim 1, wherein: the cup includes aclosed end defining the first valve seat, the second valve seat, and anactuator opening; and an open end portion defining at least a portion ofthe third valve seat; and the safety valve further comprises: a valveactuator extending through the actuator opening and operatively engagedwith the valve piston.
 11. The safety valve of claim 1, wherein thethird valve seat is closed to the vent when the safety valve is betweenthe closed position and the open position.
 12. The safety valve of claim1, wherein the valve piston includes a first valve element disposed toopen and close the first valve seat, a second valve element disposed toopen and close the second valve seat, and a third valve element disposedto open and close the third valve seat, and wherein the second valveelement and the third valve element are disposed so that the secondvalve seat and the third valve seat are open when the safety valve isbetween the closed position and the open position.
 13. The safety valveof claim 1, wherein the cup defines at least a portion of a flow pathbetween the first valve seat and the second valve seat when the safetyvalve is in the open position.
 14. The safety valve of claim 1, whereinthe cup includes a side wall that has an upper end portion of reducedwall thickness that at least partially defines the vent when the valvepiston is in the closed position.
 15. The safety valve of claim 1,wherein the cup includes a wall that has an upper end portion of reducedwall thickness, and the valve piston includes a sealing surface that isspaced apart from the upper end portion when the third valve seat isopen to the vent, and the sealing surface is engaged with the thirdvalve seat when the third valve seat is closed to the vent.
 16. Thesafety valve of claim 1, wherein the cup further defines a fourth valveseat that is open to a second vent when the valve piston is in theclosed position.
 17. The safety valve of claim 1, further defines afourth valve seat that is open to a second vent when the valve piston isin the closed position, wherein the valve piston includes an outerannular seal slidably engaged with the third valve seat when the thirdvalve seat is closed to the vent, and spaced apart from the third valveseat when the third valve seat is open to the vent, and an inner annularseal slidably engaged with the fourth valve seat when the fourth valveseat is closed to the second vent and spaced apart from the fourth valveseat when the fourth valve seat is closed to the second vent.
 18. Thesafety valve of claim 1, wherein the valve piston includes an annularseal slidably engaged with the third valve seat to close the third valveseat from the vent, and spaced apart from the third valve seat to openthe third valve seat to the vent, and the cup and valve piston areproportioned so that the first valve seat and the third valve seat areclosed when the safety valve is between the closed position and the openposition.
 19. The safety valve of claim 1, wherein the valve pistonincludes an annular surface, and the annular surface is slidablydisposed in the cup to move between the safety valve closed position;and a third valve element is spaced apart from the third valve seat inan open position when the safety valve is in the closed position.